About the same time as Teotihuacán was being founded in the Valley of Mexico, the cornerstones of another ceremonial center destined for greatness were being laid some 1000 km (600 mi) to the east. Sometime during the second century B.C., Olmec-inspired influences began to spread into the Yucatán region, carried by a people whom the archaeologists have called the "Pioneers." Surely, people of Mayan tongue had inhabited the region for many centuries in the past, but now for the first time the rise of a more advanced culture could be detected in the development of ceremonial centers with monumental structures. Although the Yucatán was a difficult environment in which to nurture an urban settlement, due to its lack of surface water, its undependable rainfall, and the stony character of its soils, the first major agglomeration in the region seems to have arisen in what has to have been the most favorably endowed area of the entire peninsula. At the risk of invoking the notion of geographic determinism, it could be said that the Mayas had located the best place first!
This was Edzná, in the interior of Campeche state about 50 km (30 mi) to the southeast of the present-day port city of Campeche. It is located on the edge of what is the largest aguada, or alluvial basin, in all of the Yucatán, and consequently had one of the most extensive agricultural hinterlands of any settlement on the peninsula as well as one of the more dependable water supplies. Founded about 150 B.C., Edzná was the earliest major Maya urban center and at the peak of its importance probably numbered some 20,000 inhabitants. It is centered on a five-story pyramid which the archaeologists have termed simply "Cinco Pisos" (Spanish for "five stories") and it is laced by a series of great canals that radiate across the aguada -- an engineering feat fully as impressive in terms of the man-days required for their construction as the pyramids of Teotihuacán. And, like the metropolis on the meseta, the layout of Edzná clearly bears the imprint of its Olmec-inspired founders, for it is once again precisely oriented to the sunset position on August 13 -- a date whose significance had been further enhanced with the creation of the Long Count since it was believed to mark "the day on which the world began". From Edzná the march of civilization continued its advance into the Maya realm, both northward into the pitted limestone landscape and scrub-forests of the Yucatán and southward into the tangled rain forests of Petén and the highlands of Guatemala. This easterly wave of expansion led to the founding of literally hundreds of new nodes of settlement amongst the Maya, most of them hardly more than modest clearings in the forest but also many of which became imposing ceremonial centers of considerable size and importance including places like El Mirador, Uaxactún, and Tikal in the Petén and later Kabah, Uxmal, and Chichén Itzá in the Yucatán. Only in a few of them were solsticial orientations to prominent mountains possible, for this was not a region of imposing topography much less of clear sight lines. In all of them, however, one or more structures can be found which commemorate the key dates of the Olmec calendar, among which the sunset position on August 13 is invariably present.
Although the layout of Edzná mimicked that of Teotihuacán by being oriented to the August 13 sunset, the Maya priests were no doubt quick to realize that, sacred as that date may have been, it had no real meaning to the peasant farmers of the Yucatán. They were also certainly aware that it was the zenithal passage of the sun that had defined that date, but at Edzná their observations revealed that the sun passed overhead at noon no less than 18 days earlier than the date that the Olmecs had established as "the beginning of time." Obviously, while the Maya couldn't change the facts of history, they could amend the calendar to accord more closely with the realities of their own physical setting.
Thanks to their knowledge of the Long Count, the priests at Edzná realized that it would not be too long before the first day of the secular calendar, 0 Pop, would coincide with the zenithal passage of the noonday sun over their city, and with the proper preparation they could "reform" the calendar in such a way as to make that their "New Year's Day". By examining the structure of the Long Count ourselves, it becomes a rather simple matter to reconstruct that event and when we do, we find that such a reform was most likely carried out in the year 48 A.D. For proof that such a change actually did take place, we can turn to no less an authority than Bishop Diego de Landa, one of the earliest Spanish prelates of Yucatán, who records that he himself witnessed the Maya New Year celebrations on the equivalent of July 26 in our present Gregorian calendar. And when we realize that the noonday sun is directly overhead on that day at latitude 19.5º N. and that Edzná is the only Maya ceremonial center of importance which is found on that parallel, then we can appreciate the very special role that this place played in Maya astronomy and time-reckoning. Indeed, glyphs from the seventh century A.D. reveal that it was the Maya priests at Edzná who were the final arbiters when a one-day correction in the calendar became necessary.
But, aside from its Greenwich-like role in setting time for the Maya world, we now know that Edzná was the Maya's earliest center of astronomical studies, for in 1978 the first lunar observatory in the New World was identified there. To all Mesoamerican societies, the movements of the moon seemed so erratic that they thought of it as being "crazy" or "drunken"; yet unless or until they could accurately chart its "weird" behavior, there was no way that they would ever know when it was next likely to be "devoured by darkness". And because eclipses were such fearsome events for the masses, any priest who learned how to foretell their occurrence would immediately become living proof that "knowledge is power."
However, in the flat and featureless landscape of Yucatán it was quite impossible to find a natural feature that could serve as a marker for the Mayas' horizon-based observations, so they were obliged to create such a "marker" for themselves. From their vantage point atop their five-story pyramid, the priests had an unencumbered 360º view of the heavens but only as the moon neared the horizon could its position be defined. What was required was to find at least one extreme position from which a count could begin and the idea was to see how long it would take for the moon to return to that same point again. Little did they know as they undertook this exercise that it would take them 18.6 years to calibrate even one such cycle, and, to ensure that their count was correct, would entail repeating the count at least once more. Thus, assuming that their endeavor was attended with a modicum of good luck, they might have carried it off in a minimum of a little over 37 years, but that does not seem to have been the case. The very first lunar inscriptions that we find on Maya stelae go back to A.D. 357, which strongly suggests that by that time they may have been working on the problem for nearly 300 years! Still other evidence from the middle of the 8th century reveals that, while the basic mathematics of the problem seem to have been finally worked out, complete success in predicting eclipses continued to elude them even then. In any case, at Edzná itself the enduring witness to this challenging enigma is to be found in the ruins of a lofty pyramid known as "La Vieja" -- "the ancient one" -- constructed just high enough to intersect the horizon as viewed from Cinco Pisos and sited precisely at an azimuth of 300º from it, marking the northernmost still stand of the moon as accurately today as it did when it was built ten centuries ago.
By the time that Teotihuacán was beginning its meteoric rise as the major metropolis of the New World and the Maya priests were busying themselves with trying to make sense out of the movements of the moon, the Olmec era had already come to an end. The Olmecs' brilliant burst of creative energy in the arts, astronomy, and mathematics coupled with their dynamic expansion of city-building and long-distance trade was not matched by a sufficiently large population base to result in anything like a consolidated political entity. As "missionaries" they had been successful in passing on a rich intellectual heritage to peoples as geographically dispersed as the Totonacs and the Teotihuacanos, the Zapotecs, the Mixtecs, and the Maya, but it remained for each of the latter to develop their own identities within the economic, social, and political fabric of Mexico. And, not surprisingly, each of their societies came to develop a personality that strongly reflected its own regional geography.
Of the new "states" which emerged in the wake of the Olmec passing, Teotihuacán was the most vigorous and expansive. Whereas it may have begun purely as a ceremonial center, its obsidian outcrops soon made it into a hub of craftsmanship and commerce as well. Its warm-temperate climate, while suited to the seasonal cultivation of such staples as maize, beans, and peppers, was too marginally cool to permit the production of either cotton or tropical fruits, so these had to be imported from the Gulf coastal lowlands along with such exotic items as the plumes of colorful birds, cacao, vanilla, and rubber. From yet-more-distant sources came precious stones such as jade and gold dust. When it is remembered that there were no beasts of burden in Mesoamerica -- save man himself -- the extent and volume of trade that went on between the growing metropolis and its constantly expanding hinterland was indeed most impressive. Because of its location virtually within sight of the northern grasslands and desert, Teotihuacán was essentially a frontier outpost of Mesoamerican civilization; hence it looked primarily to the east and south for its foodstuffs and raw materials as well as for markets for its obsidian, ceramics, and various other handcrafted goods. By the same token, as an urban node, it had no viable competitor of any size within several hundred kilometers, save perhaps Cholula, a pilgrimage site in the basin of Puebla to the east.
To the west of the Valley of Mexico, beyond a pine-forested ridge some 3000 m (10,000 ft) in height, lay the yet loftier and cooler basin of Toluca. Here are found the headwaters of the Río Lerma, a river that descends in "steps" from one highland basin to the next on its course toward the Pacific. Although the Lerma itself terminates in Lake Chapala, the Río Grande de Santiago, Mexico's largest Pacific-flowing river, carries its waters from the lake to the ocean through a highly dissected region of steep-walled canyons. Thus, it is perhaps not too surprising that the Olmecs who first ventured into the Valley of Mexico were not particularly tempted to probe farther into these less hospitable regions of the Mexican west. But, despite the fact that western Mexico lay beyond the influence of the Olmecs and hence outside the cultural pale of Mesoamerica, its ties with the more advanced societies of South America continued apace through the entire span of the Olmec era.
From their mountain top city at Monte Albán, the Zapotecs dominated the broad Y-shaped valley of the Río Atoyac and its tributary in the highlands of Oaxaca, and also exerted control as far as the Pacific coast along the corridor of the Tehuantepec River. But, surrounded as they were on all sides by rugged mountains, they found little temptation to extend their dominions into areas whose isolation had already fragmented the peoples who inhabited them into a score of different linguistic groups. Moreover, in the mountains to their north lurked the Mixtecs, against whom they always were obliged to direct a watchful eye.
Compared to the expansive feeling that the more open landscapes of the Mexican highlands tend to produce in the viewer, the rainforests of the southern Yucatán and the Petén give one an almost claustrophobic sensation instead. In this tangle of exuberant verdure -- so familiar to the Zoque and Olmec -- the Maya struggled to wrest a foothold wherever the trees could be felled to make way for their corn patches. Because their resultant settlements had hinterlands that were relatively limited in scope, most of them remained modest in size and in power. The long-held notion that the Maya were a peaceful people primarily dedicated to intellectual pursuits has had to be abandoned, however. More and more evidence has come to light that, rather than being organized into some kind of over-arching "empire," they were instead separated by their rain forest environment into hundreds of small, competing city states, and that warfare was virtually endemic among them. On occasion, of course, several of the city-states may have united to form military alliances, as seems to have occurred in the long series of struggles between such places as Tikal and Calakmul. In any event, wall paintings of battling warriors and captives being tortured figure prominently in Maya art work. Ruins of fortifications, walls, and moats reveal that the need for defense has been a paramount concern of the Maya ever since Edzná itself was founded. Clearly, in a region devoid of other enemies, the feared attackers could only have been their neighboring Mayas.
But, if the Maya did not succeed in erecting political entities of more than local or regional importance, this was certainly not the case with the dynamic metropolis of Teotihuacán. Already as early as 300 A.D., it had extended its cultural and commercial influence as far south as the ancient Olmec site at Kaminaljuyú (where Guatemala City stands today), for unmistakable evidence of its art, architecture, and ceramics show up there at that time. By the end of the same century its influence was also clearly apparent amongst the Maya, and in such centers as Uaxactún and Tikal they may even have taken over positions in the ruling elite.
From a geographic perspective, two of the most interesting manifestations of Teotihuacán's growing cultural and commercial domination took place in the first half of the 5th century A.D. In what probably comes the closest of any ventures undertaken in Mesoamerica in the name of "pure science", the priests of Teotihuacán launched two expeditions to opposite ends of their "known world" in order to find answers to questions which must have intrigued them for some time. One of the expeditions was dispatched from their own city into the northern desert, its mission being to find "where the sun stopped" on its annual migration each summer. In other words, they were curious as to why it went "just so far" each year and no farther, before it again turned to the south. Rephrasing their question in the vernacular of Western science, they were asking, "where does the summer solstice -- the basis of the secular calendar -- take place", or, more simply, "where is the Tropic of Cancer”.
The second expedition was to be launched in a southerly direction and its goal was determine just where it was that the sun passed vertically overhead on the August 13. If this "place" could be located, perhaps the birthplace of the sacred almanac could be found -- and perhaps even the earthly paradise that their myths called "Tamoanchan", a lush tropical garden of cacao trees and corn plants, of bountiful fruit and wild game, of beautiful birds and dazzling dragon-flies. Clearly such an expedition could be more rationally carried out by the Maya, because it seemed obvious that they must live geographically much closer to this fabled land than did the Teotihuacanos. Thus, although couched in religious terms, the questions that these two expeditions set out to answer were fundamentally sound scientific queries.
The trek into the northern desert appears to have clung close to the foothills of the Sierra Madre Occidental where the likelihood of finding water was greater than out in the middle of the meseta or along the arid back-slope of the Sierra Madre Oriental. In any event, this is where we find the "observatory" built by the Teotihuacanos, located on an open hillside next to a small stream and looking eastward toward a group of isolated mountain peaks that break the distant horizon. Without the benefit of more than their own careful observations, they chose a site which lies within 2 km (1.25 mi) of the Tropic of Cancer at a place known to the native Americans as Chalchihuites, or "the place of the green stones", and in Spanish as "Alta Vista" -- "the high view" -- near the western border of the modern state of Zacatecas. The "observatory" which they constructed consists of two parts, one which embraces a series of trenches cut through the hillside and plastered over with adobe to preserve them from the elements and a second which consists of a temple or courtyard with 28 pillars that increase in diameter toward the middle of the structure and then decrease toward its outside corner. It is quite obvious that the trenches were meant to define key astronomical alignments, for as one sights along the principal trench, a sharp peak known as Cerro Picacho is seen to mark the horizon where the sun rises at the summer solstice. On the other hand, the courtyard with the pillars of varying diameters appears to have been an attempt by the Teotihuacanos to chart the changing phases of the moon.
The expedition that headed south out of Tikal through the rain forest was faced with environmental and "scientific" problems of quite another nature. Instead of defining a place where the zenithal sun stood still, they were looking for a place where it passed overhead with a cyclic regularity of 260 and 105 days. The route that was taken most probably lay along the water-divide between the Caribbean Sea and the Gulf of Mexico where Tikal itself had been sited. Such a route would skirt both the granite ridges of the Maya Mountains to the east and the vast swamps of the Usumacinta headwaters that lay to the west. As the limestone crests of the Cuchumatanes loomed on the southern horizon, the expedition probably swung east around Lake Izabal before entering the long seismic trench of the Motagua river. Opening southwestward into the highlands, the Motagua valley afforded an easy route into the interior but when it started curving more west than south, it had to be abandoned for one of its tributaries -- the Río Copán -- instead. Ironically, by the time they reached this point, the Mayas found themselves in a strange and hostile environment, a pocket so totally cut off from the trade winds by the surrounding mountains that it supported only a semi-desert form of vegetation. Yet, the fact that a clear stream of fresh water entered it from the south encouraged them to venture higher up the valley, and as they did so, they saw the drab desert browns of the scrub-thorn trees gradually give way to the forest greens of thick stands of pine and oak. At an elevation of more than 600 m (2000 ft), the valley broadened out as the river slowed its pace in a series of sweeping meanders and it was here that the priests jubilantly announced, "This is the place". Here they could measure an interval of 260 days between the passages of the zenithal sun, and though it certainly was not the tropical paradise that their Teotihuacano sponsors had imagined, it did meet the criteria of the "place where time began". In a sense, for the Maya it represented a "homecoming" in an otherwise alien land, for they had discovered a place where the sacred almanac -- the very essence of their preoccupation with time -- could be calibrated as it had "in the beginning", but in an environment with which they were quite unfamiliar. Copán, the ceremonial center that they founded here, was to become not only the southernmost major center of the lowland Maya civilization, but ultimately one of its most important astronomical centers as well. Its earliest Long Count stela dates to the year A.D. 426.
The centuries following these two remarkable expeditions surely represented the "Golden Age" of civilization in Mesoamerica, with Teotihuacán continuing to grow in both wealth and power. Indeed, at this juncture in history, it ranked as one of the three largest cities in the world, along with Rome in Europe and Beijing in China, for its population probably numbered as many as 200,000. While most of its energies continued to be directed to its extensive hinterland in the east and south, beginning about A.D. 600 it suddenly became aware of ominous developments on its exposed northern frontier. Although the semi-desert expanses of the meseta had never supported more than marginal numbers of Uto-Aztecan speaking nomadic hunters and gatherers -- savages known to their civilized neighbors on the south as "Chichimecs, or "dog people", -- the onset of drought in these regions now began making their already precarious existence even more difficult. Whether it had been Teotihuacán's astronomical expedition to the Tropic of Cancer that had first alerted the nomads to the existence of the great city in the south or if the push of other nomads out of the American Southwest was already driving them southward, the tribes of the meseta increasingly cast envious eyes toward the moister, greener areas that surrounded the bustling metropolis in the Valley of Mexico. The first people to be impacted by their advance were the Otomís, who occupied the highland basins just to the north and west of Teotihuacán, and, when faced with the choice of fighting the barbarous nomads or of fleeing to the city, they chose the latter. While their own intentions may not have been hostile, the Teotihuacanos certainly could not have been expected to welcome a flood of refugees with open arms, and the resultant struggle caused the city serious economic, social, and political dislocations. Even so, the Otomís were only "the tip of the iceberg," for the real collision of cultures came somewhat later when the Uto-Aztecans themselves -- the "Chichimecs" -- burst into the Valley of Mexico. With the arrival of the first wave of them, the Toltecs, the city's fate was sealed, for the charred timbers of Teotihuacan's palaces reveal that it was put to the torch about A.D. 750.
It can hardly be imagined what the fall of Teotihuacán must have meant to the peoples and cultures of Mesoamerica. By way of a modern analogy, it could perhaps be likened to the repercussions that the total destruction of a New York or London would have on the world's economic and cultural life. Yet, because it was the only metropolis of its size and significance in the New World, its loss must have been even more keenly felt.
Not only did the fabric of long-distance trade break down, but also it was as though the very heart and brain of the region had suddenly stopped. Refugees from the city fled to the south and east taking with them only what they could carry in their arms and minds. Some sought sanctuary on a mountaintop near the present-day city of Cuernavaca where they built a defensively conscious ceremonial center that we know today as Xochicalco. Others poured across the mountains into the basin of Puebla, finding only temporary refuge at Cholula, for the Toltecs soon overran that place as well. Still others continued down slope into the eastern rain forests where they took up residence in the ceremonial center of El Tajín, almost hidden amidst the karstic hills of what is now northern Veracruz state. But these survivors of the holocaust -- the elite, without question -- could only have been a small number of the original population of Teotihuacán, the remainder of who now found themselves struggling to keep alive without the infrastructure and security of an urban exchange system. For them, the great majority, it was as though the clock had been turned back to the days of a subsistence economy, and no doubt within a relatively short time the city must have been all but abandoned as its survivors shrank back into the countryside to fend for themselves as best they could.
Ironically, it was just as Teotihuacán was undergoing the trauma of its conquest and destruction that the Maya were nearing the peak of their development. At Tikal, five skyscraper pyramids, all of them ranging from 50-60 m (160-200 ft) in height, were rising tier on tier out of the jungles of Petén, crowning the architectural glory of a city which now numbered perhaps 50,000 to 60,000 inhabitants. Fittingly, each of these lofty temples had been sited with such accuracy that together they comprised an astronomical matrix which served to mark several key dates of the Maya year, including sunrise on the winter solstice, sunrise and sunset at the equinoxes, and, of course, sunset on August 13.
As the architectural grandeur of Tikal took shape in the mid-eighth century A.D., so too, did the intellectual achievements of the Maya culminate about the same time. One of the few Maya books to escape the bonfires of Bishop Landa is an astronomical manuscript known as the "Dresden Codex" whose initial dates go back to the year 755. It reveals that by that time the Maya had finally worked out the mathematics of eclipse prediction, for the Codex begins with a solar eclipse on November 15, followed by a lunar eclipse on November 30, and another solar eclipse on December 15. Yet, due to the bitterest of ironies, correct as their mathematics were, the Maya did not have the satisfaction of actually seeing any of the events they had predicted; although the first solar eclipse was a "near-miss" as viewed from the Yucatán, the lunar eclipse was visible half a world away over the Indian Subcontinent, and the path of the second solar eclipse lay between South Africa and Antarctica where probably not a single human being observed it! Small wonder, then, that when the Maya foresaw another lunar eclipse coming about eight years later, they appear to have convened a "convention" of their priest-astronomers at Copán to observe it. This time their predictions were crowned with success because just after sunset on June 28, 763 they watched the disk of the full moon rise in total darkness. They obviously were so elated that they commemorated this memorable date no fewer than eight times on six different altars, stelae, and buildings at Copán!
But, for the Maya the opportunity to enjoy their architectural and intellectual achievements was destined to be all too brief. Within less than a half-century one after another of their splendid ceremonial centers began to be abandoned and swallowed up by the jungle. Palenque went first about A.D. 810, followed shortly thereafter by Yaxchilán and Piedras Negras about 825. By the 840's the material existence of the remaining Maya cities was deteriorating markedly and by the end of the century the rain forest had already reclaimed most of the settlements in the Petén and the southern Yucatán.
Archaeologists have long puzzled over what it was that triggered this precipitous collapse of Maya civilization, some attributing it to environmental factors, others to cultural ones. Climatic change has been one of the primary physical causes advanced, and "evidence" purporting to support both drought on the one hand and increased precipitation on the other have been put forth. Another theory argues that, although the climate probably remained fairly constant, the real cause of the collapse was soil depletion; after many generations of farmers repeatedly growing corn on the same plots of land, the soils simply wore out, especially as the increasing pressures of population growth precluded their fallowing for any restorative period. With the breakdown of the food supply system, the further scenario of administrative and social collapse was inevitable.
Hypotheses that look to a cultural explanation of the Maya's downfall tend to stress war, civil unrest, or disease as a causative factor of societal decay. Certainly, war had been a part of Maya culture since its earliest beginnings so it cannot be ruled out. Only, one wonders if and how it could have risen to such a level as to destroy the entire civilization, and why it would have done so in a "wave" that seems to have moved from west to east across their realm -- unless the "culprits" were invaders from the outside. But, if the latter were the case, why do we not find some evidence of their "conquerors"?
As regards the civil unrest hypothesis, any number of possible "triggers" suggest themselves: a farmers' rebellion against repeated levees of public-works projects by the priestly caste; internal bickering between heirs-apparent to the power structure could have fractionalized the public as well. Or, perhaps new and different interpretations of religious dogma became the divisive "straw that broke the camel's back." One could, of course, go on suggesting all manner of such potential causes for dissension, but alas, without the satisfaction of knowing which, if any, of them is correct. In the same way, any evidence that there might have been of widespread mortality caused by disease is totally lacking, for in the humid climate of the Petén, especially, skeletal remains are quickly decomposed.
Concerning our earlier discussion of the role of climate in the demise of the Maya, there is intriguing geomorphic evidence which lends support to the thesis of an increasingly wet climate in southeastern Mexico during the Late Classic Period (A.D. 600-900). The westernmost site ever constructed by the Maya was Comalcalco, which lies in the heart of the swampy lowland called Chontalpa, some 40 km (25 mi) to the northwest of the modern city of Villahermosa, the capital of Tabasco state, and some 16 km (10 mi) from the coast of the Gulf of Mexico. It is located on the right bank of the Río Seco ("Dry River") at an elevation scarcely 10 m (33 ft) above sea level. Situated in the midst of an extensive alluvial lowland, Comalcalco had no easy access to building stone of any kind, hence, in this one place and nowhere else the Maya constructed their buildings of fired brick, giving the site a totally unique character among Mesoamerican ceremonial centers.
But Comalcalco is unique in another way as well. At the time of its construction, it apparently served as a seaport -- most probably for Palenque and the hinterland of the Grijalva valley, which lay to the southwest. In its heyday, Comalcalco may, in fact, have lain on or immediately back of the coast, for the continuous sedimentary deposition of the great rivers in this region has since pushed the shoreline farther and farther out into the shallow waters of the adjacent Gulf. At the same time, the block of the earth's crust beneath the giant, compound delta has been sinking under the weight of the accumulating sediments, for today the footings of most of Comalcalco's buildings are standing in water -- not too unlike the conditions found in Venice.
Sometime, probably in the Late Classic Period as the climate grew wetter, the Grijalva River overflowed its banks and made a drastic shift in its channel just upstream of the present-day city of Cárdenas. Turning sharply eastward, it abandoned its older, more direct route to the Gulf and spilled into the vast swampy plain where the immense Río Usumacinta and its myriad tributaries all come together. Comalcalco, the former seaport and gateway to the great Grijalva Valley, was now left "high and dry" along the empty water-course of the Río Seco -- without a hinterland to serve and quite cut off from any overland contacts it may have had earlier with the Maya core area to the east. Certainly, if there had been any Maya settlements and ceremonial centers in the immensely fertile river valleys between the Grijalva and the Usumacinta -- and it seems almost unthinkable that the Maya had not seen fit to utilize this region -- all traces of them were swept away in the resultant flood. Although the effects of this cataclysm may have been limited to the immediate Chontalpa region, it is very possible that they were, in fact, just the most dramatic manifestation of a changing climate that was soon to engulf the entire Maya society. In a rain forest environment, drought would have meant a respite from too much precipitation, whereas added moisture could only have spelled disaster because the use of fire in clearing the land would have become more difficult, the forest would have re-grown more rapidly, and the soils would have been depleted more quickly. In any event, within the next few decades the rampant growth of jungle vegetation had swallowed up most of the remaining Maya cities and what had once been a thriving urban population of perhaps 12 million had fallen to an impoverished rural population of less than 2 million.
While spreading drought was causing the Uto-Aztecans to put the Otomís and the Teotihuacanos to flight on the Mexican plateau and the Mayas were slowly succumbing to the advancing rain-forest in the Petén, an event of quite another type was taking place in the west of Mexico. Sometime about the eighth or ninth century A.D., a sea borne people appear to have arrived on the coast of Michoacán in sufficient numbers to have had a disruptive effect on the settlement pattern which existed in that part of the country. Calling themselves the Purépecha, which in their language meant "the late comers" or "recent arrivals", they seem to have made their original landfall in the vicinity of the Balsas river and then spread inland and upstream from there. Apart from the coastal fringe of the river mouth itself, the country in which they found themselves was the hottest and driest part of southern Mexico -- the desert basin of the Balsas Depression -- a region which may well have been a population void before their arrival. In any event, the Purépecha quickly realized that the Balsas had little to offer them other than metallic ores, such as copper, silver, and gold, and while they had the technology and skills to smelt and fashion metals, they certainly could not derive their sustenance from them. Thus, it was almost inevitable that they would seek the solace of the cooler, damper, forested uplands where they could cultivate their crops and build their homes. The region that beckoned them was the volcanic highland of Michoacán, an upland of productive soils and pine-clad mountains liberally sprinkled with sparkling lakes teeming with fish and aquatic birds. That such a land had gone previously unsettled seems hardly likely, but just which peoples the Purépecha displaced to take possession of it is somewhat unclear. Surely, the Mixtecs, or "cloud people" on their southeast were probably jostled by their arrival, for about this time the Mixtecs began a concerted southward advance against their longtime neighbors in the valley of Oaxaca, the Zapotecs. They may also have played a role in dislodging the hapless Otomís as well. Yet another people who were likely set adrift by these migrations were the Chiapanecs, whose original homeland is unknown but who ended up pushing southward into the north-western corner of Chiapas state -- to which they gave their name -- and there being ultimately absorbed by the Zoque. The Purépecha dominions came to coincide almost perfectly with the drainage basin of the Balsas, which today coincides nearly exactly with the state boundaries of Michoacán; both of these natural and political regions can, in turn, be delimited by the areal extent of the Purépecha language and its place-names.
The Purépecha (known later to the Spanish as "Tarascans") were in almost every way strikingly different from their neighbors. Not only was their language totally unrelated to any of the native tongues around them, but their culture was also quite unlike that of the Mesoamericans. They dressed differently, they cut their hair differently, they knew the use of metal and their neighbors did not, and their gods and religion were different. Obviously, the Mesoamerican calendar with its intertwined pantheon of gods and rituals was totally unknown to them, and despite their precocity in fashioning metals, they seem to have been noticeably lacking in mathematical and astronomical knowledge. Quantification to the Purépecha was defined as "one, two, and many", whereas their interest in celestial matters seems to have focused on the Southern Cross -- suggesting that their native home may well have been in western South America, from which they brought the knowledge of metallurgy. In any event, their critical role in influencing the life of Mexico still lay several centuries in the future.
Thus, by the eighth century A.D. the greatest city in New World lay abandoned and in ruins, the Toltec barbarians were struggling to consolidate their hold over the northern fringes of the Mesoamerican cultural realm, and an alien people from beyond the sea had established an impregnable bridgehead in the west. Once the embers of Teotihuacán had cooled, the Toltecs must have experienced a certain numbing realization of what they had done. The economic, social, and political life of the bustling metropolis had been replaced by a void, and its cultural and intellectual life was all but dead. One of the casualties of their conquest had been the calendar, of which it is probably safe to say they had known nothing as they swooped down on the city. But once they "interviewed" the survivors, they quickly came to appreciate that this unseen, mystical force had been the engine that drove the entire civilization. It was inexplicably bound up with the gods; it ordered the lives of the people; it gave meaning to the notion of time. Understandably awed by what they learned, they immediately set about trying to reconstruct the calendar as best they could, though with the priestly caste long departed, they had only untutored, secondary sources on which to rely. Thus, it is all the more remarkable that they came up with as reasonable a facsimile of the calendar as they did.
To be sure, there were aspects of the calendar which they either did not understand (for instance, the rationale behind the August 13 sunset), or whose value they did not appreciate (such as the importance of zero or the use of a bar symbol to write the number "5"), or which simply became garbled (as for example, the substitution of the winter solstice for the summer solstice in determining the beginning of the new year). Moreover, they had some innovations of their own which they added to the calendar, such as the zenithal passage of the Pleiades to define when one 52-year period came to an end and another began -- an event which they called the "binding of the years" and whose occasion they commemorated with a special form of human sacrifice.
From the internal structure of the calendar that the Toltecs devised it is very likely that it was set in motion in the year A.D. 778, so this reveals how quickly they had felt the necessity of re-establishing a time-count. Indeed, the Toltecs were so captivated by the notion that "history repeated itself" every 52 years that they concluded the present world, or "sun", must have been created just 52 years earlier, i.e., in A.D. 726! Naive as this idea was, it did reflect a belief common to all peoples of the Mesoamerican realm, namely that the present world was the Earth's fifth reincarnation, each of the four previous worlds, or "suns", having been terminated by such disasters as being devoured by jaguars, consumed by fire, destroyed by wind, or submerged by floods. Because the present world, or "fifth sun", had begun on a day named "4 Earthquake", they were convinced that devastating temblors on another day with the same name would destroy it.
The first site chosen by the Toltecs for the city that they intended to take the place of Teotihuacán was at Ixtapalapa, on the southeast side of present-day Mexico City and scarcely 12 km (7mi) from the lava-covered ruins of Cuicuilco. Having no experience in urban planning, they must have soon discovered that its marshy site was not the best to build on and its situation offered little advantage to trade, so a new, more strategically located capital was founded at Tulancingo some 100 km (60 mi) to the northeast some time later. Although it had firmer footings and controlled the entrance to a precipitous pass leading to the coastal lowlands, it too, was soon abandoned for a third capital located at Tula, 100 km to the west. This capital was founded by a chieftain whose name was "Ce Acatl Topiltzin", who later took for himself the title of the ancient culture hero of Teotihuacán, Quetzalcóatl, or "the feathered serpent". Despite a long reign of peace and prosperity in his new capital, a power struggle within the Toltec hierarchy forced Quetzalcóatl to flee with his retinue to the Gulf coast in the year "Ce Acatl", or "1 Reed", which would have been the Christian year 999. Although the deposed king died on reaching the coast, legend has it that he was subsequently reincarnated as the morning star, i.e., the planet Venus, having vowed to return one day to rightfully reclaim his throne. His retinue continued to the east, arriving on the coast of Yucatán, and then moving inland to subjugate the by-then almost moribund Maya city-state of Chichén Itzá.
Although Tula was a rather pale copy of the great metropolis the Toltecs had destroyed, it gradually grew to support a population of some 30,000 to 40,000 inhabitants and its trading network extended as far south as the Nicoya Peninsula of Costa Rica (from which it imported polychrome ceramics), eastward into the Yucatán Peninsula, and as far northward as the present-day southwestern United States (where the architectural influences of both Tlaloc, the rain-god, and Quetzalcóatl may be identified). Interestingly, although Plumbate pottery from Soconusco shows up in Tula, no metal has ever been found there, despite the fact that the Toltec period is known to have coincided with the first appearance of metallurgy in Mesoamerica. Antagonism with the Purépecha, the first practitioners of the new craft, may well be the explanation. Nonetheless, mining colonies had been established in the northern desert -- probably as early as Teotihuacáno times -- to supply semiprecious stones to the civilizations of Central Mexico, but about the year A.D. 600 a southward retreat had begun which had all but abandoned the Chichimec "outback" to the nomads by 850. A Toltec re-expansion into this region appears to have taken place about 900, and Casas Grandes in northwestern Chihuahua seems to have been a thriving Toltec trading post by about 1050. Perhaps a reoccupation of the "observatory" at Chalchihuites occurred about the same time, for a further trench marking the sunrise on February 12 -- the date the Toltecs selected as their "New Year's day" -- was apparently added then.
It would seem that the neighbors nearest to the Toltecs who received the most cultural impact were the Mixtecs. Although they had originally received the calendar by way of the Zapotecs, together with the hieroglyphic system of dots and bars to record numerals, under Toltec influence they abandoned the use of bars. As a result, we find that all of the beautifully colored Mixtec codices that have been preserved define calendar dates only with dots.
As we have already noted, contact with the Maya area of the Yucatán was not limited to commerce because about the year 1000 Toltec warriors moved in to establish a new militaristic regime in the old ceremonial center of Chichén Itzá, not only giving the place a new lease on life but materially altering its architecture, art, and religion as well. Not the least of these cultural influences was the introduction of the cult of Quetzalcóatl, who became known to the Maya by the name of Kukulcán.
In the west of Mexico certain influences from the central plateau had begun to show up from about A.D. 300 on at such sites as Ixtépete near modern Guadalajara and at Ixtlán del Río in the borderlands of Nayarit, but these contacts were considerably strengthened during Toltec times. Perhaps the most eloquent testimony to the geographic diffusion of the calendar by the Toltecs is the fact that we have indisputable evidence of its presence in the far reaches of Pacific Mexico by at least the early decades of the twelfth century. As the Codex Botturini makes abundantly clear, when the Aztecs began the migration which took them from their homeland in the marshes of Aztlán to the small rocky islets in Lake Texcoco which ultimately became the spectacular capital city of the vastest indigenous empire Mesoamerica was ever to know, each move along the way was documented both in space and in time. Whereas many of the place-names they used can only be guessed at (e.g., "place of the sand spider", or "place where spear-throwers are made"), the temporal sequence of the events that transpired can be precise pinned down year by year.
The Aztecs record that their departure from their island home (subsequently identified as Mexcaltitán on the coast of Nayarit) occurred in the year "1 Flint-Knife". Because they already knew the significance of the "binding of the years" ceremony, they celebrated four such events in the years "2 Reed" while en route. Four years after the last of these celebrations -- in the year "6 Reed" -- the narrative ends abruptly, due to the Codex Botturini having been damaged. Yet, from the evidence at hand, it is obvious that their migration took some 187 years to complete. This is because there are 27 years between "1 Flint-Knife" and the first occurrence of "2 Reed," and 52 years between each recurrence of a year of that name, followed by four additional years -- i.e., 27 + 52 x 3 = 27 + 156 = 183 + 4 = 187. Inasmuch as their arrival in the Valley of Mexico is known to have taken place about the beginning of the fourteenth century, this would mean that their departure date was most probably in the year 1116.
Ironically, most of the ancient native accounts herald the beginning of the Chichimec period with the next time the year "1 Flint-Knife" occurred -- i.e., 52 years later in 1168. This is because earlier in the decade, Tula, the capital of the Toltecs, had been overrun by barbarian Chichimecs and put to the torch. In the Codex Botturini the Aztecs record that they had left the "place of the reeds," or Tula, in the year 1163, so there is strong circumstantial evidence that it was the Aztecs themselves who had been the culprits. Just as the Toltecs had been the undoing of Teotihuacán, so the Aztecs appear to have been responsible for bringing down the remnants of the first Nahua civilization on the plateau of Mexico.
Ultimately, the irony was to become even greater, for once they became fully aware of what they had done, the Aztecs revived the memory of the Toltecs as the greatest people who had ever lived. They were heralded as the first people who had learned to count, the first to understand the movements of the sun and to measure the passage of time, and the most consummate artisans who had ever molded clay or worked in feathers or textiles. Indeed, the highest compliment an Aztec could pay to anyone was to liken him to a Toltec!
As might have been expected, the Aztec migration essentially followed the line of least resistance. This was the corridor afforded by the Río Santiago, Mexico's second-largest Pacific-flowing river, and by its major tributary, the Lerma, whose headwaters rise in the highland basin of Toluca, some 100 km (60 mi) to the west of the Valley of Mexico. The basin of Toluca, however, was not an especially attractive goal in its own right, for it was the loftiest of all the intermountain basins of the Mexican plateau. With an elevation of 2640 meters (8660 ft), it was both cold and arid compared to the Valley of Mexico just over the next mountain ridge to the east. Moreover, in the middle course of the Río Lerma, the Aztecs most probably ran afoul of the Purépecha, or Tarascans, and therefore may have been obliged to detour north and eastward along the valley of the Río Turbio instead, thus ending up in the open plains to the north of Tula. On the other hand, it is just as likely that the urban metropolis of the Toltecs had been their goal from the outset, and that they had moved upstream toward it as directly as they could. In any event, as the Codex Botturini informs us, the Aztecs had reached Tula by the year 1145 and did not depart until 1163.
Whereas the place-name evidence indicates that the first phase of the Aztec migration had brought them into what is now the state of Hidalgo, most of the places mentioned in the second phase of their account have been identified with localities in the present state of México. At the close of this second phase, they had reached Chapultepec, on the western outskirts of modern Mexico City, and celebrated their fourth "binding of the years" ceremony in 1299. Of the third and final phase of their migration, all of which focused on the Valley of Mexico, only the fragmentary record of four years remains, though it is generally agreed that the actual founding of Tenochtitlán can be assigned to the year 1325.
The Valley of Mexico not only lay some 400 meters (1300 ft) lower than that of Toluca, and thus enjoyed a somewhat more temperate climate, but it also embraced the largest body of water on the entire Mexican plateau -- a feature sometimes known as the Lake of the Moon. Although it consisted of basically one extensive articulated basin, it had three major components, partially separated from one another by higher ridges of land that formed irregular peninsulas. The southernmost arm of the body of water was known as Lake Chalco, whereas the largest and most central portion was known as Lake Texcoco, and the northern arm was called Lake Xaltocán. The marshes along the edges of the lake had very early come to be appreciated for their abundance of waterfowl and for such aquatic animals as the axolotl, a large salamander that was esteemed for its flesh.
Technically, the Lake of the Moon was what the geomorphologist calls a playa lake. As such, it was chiefly fed by run-off from the adjacent mountains, and therefore it was seldom very deep. Depending upon the amount of summer rainfall received, the lake was often very irregular in volume and in shape as well. Naturally, the longer the dry season continued, the more the water evaporated and the more the lake's shorelines contracted. At the same time, the brackishness of the water increased as the proportion of dissolved salts in the remaining water rose toward the saturation point and then began to crystallize out in the form of saltpans along the edges of the lake
Had the Lake of the Moon been a classic playa lake, it would, of course, never have been the magnet for human settlement that it actually was. This is because, in addition to the summer run-off, its water supply was augmented by seepages of ground water out of the volcanic formations on the south and, especially, the southwest sides of the lake. Because this water had percolated through lava rather than through limestone it contained little or no dissolved salts and was therefore fresh rather than brackish. Indeed, having been filtered through the volcanic formations, it was also cold, clear, and pure, so a more fortuitous combination of circumstances can scarcely be imagined -- a plentiful supply of water on the very edge of a semi desert basin. (The Aztec glyph for Chapultepec very pointedly depicts the flow of water from beneath the mountain.)
Unlike typical playa lakes in other of the highland basins of the Mexican plateau, the Lake of the Moon had drawn settlers to its shores through all of human history. We know, for example, that prehistoric man was hunting mastodons on the shores of the lake as early as 11,000 B.C., and the first agricultural villages on its shores date to about 1500 B.C. The earliest "Olmec"-inspired settlements at Tlatilco, Tlapacoya, and Cuicuilco were sited near the western and southern edges of the lake as well, perhaps at least in part because the freshest waters of the lake were to be found in these quadrants. Certainly by the time the Aztecs arrived in the Valley of Mexico in the late thirteenth century, all of the best land surrounding the lake had long since been occupied. Indeed, at the time of their arrival, the western, southern, and eastern shores of the lake had been consolidated into the three distinct kingdoms of Atzcapotzalco, Culhuacán, and Coatlinchán, respectively, so it was into this political constellation that these newly arrived barbarians from the west intruded at the beginnings of the fourteenth century.
Needless to say, the Aztecs were not particularly welcome in the already relatively densely settled Valley of Mexico, for it was all that the local inhabitants could do to feed themselves in this marginal semiarid upland environment. According to the Aztecs' own tribal legend, the god of war, Huitzilopochtli, had promised that their migration would be over when they found an eagle with a rattlesnake in its beak sitting on a cactus on a small rocky island -- surely a combination of signs that they would not be likely to miss. Perhaps it was this augury that led them to look in the middle of the Lake of the Moon for their "promised land." On the other hand, another version of their arrival in the basin of Mexico states that when they asked for land on which to settle, they were offered a couple of small rocky islets in the middle of the lake roughly equidistant from each of the existing cities. -- essentially a "no-man's land" inhabited only by rattlesnakes and scorpions. Indeed, it has been suggested that this was done in the hope that the latter would make short work of the Aztecs, but apparently the willingness of a starving Chichimec to eat almost anything had probably been overlooked. In any case, to acquire sufficient land on which to settle, the Aztecs set about driving stakes into the shallow lake bottom and then scooping up mud and stones to build out the perimeters of their islands, much as they witnessed had been done in the heavily cultivated chinampas (sometimes erroneously referred to as "floating gardens") around Xochimilco at the south end of the lake. Thus, with an immense input of arduous and disciplined labor, the Aztecs gradually transformed the little rocky islands of Tenochtitlán and Tlatelolco into the nuclei of two intensely cultivated garden cities, the former serving as their religious and political nerve center while the latter increasingly took on the functions of a busy marketplace.
It should be noted in passing that whatever scenario one prefers for the founding of the Aztec capital, its siting had nothing to do with such concerns as solsticial orientation. There was no real choice as to where the city should be located, for its foundations were fixed by the geographic "accident" of the two little islands in the middle of a lake in which none of the original inhabitants of the Valley of Mexico had any interest or saw any value. It was an extremely difficult site on which to build any kind of a permanent settlement, but once the city had begun to take shape the advantages of its location gradually became increasingly apparent. From a commercial standpoint it was easily accessible to watercraft carrying foodstuffs and other bulky supplies from the adjacent shores of the lake, and from a military standpoint it was sufficiently buffered by the surrounding expanses of water to enjoy a very defensible location. Therefore, although Tenochtitlán possessed none of the astronomical significance of many earlier Mesoamerican ceremonial centers, what was initially a very difficult site was ultimately transformed into a central place with a situation of paramount importance.
Several decades were to pass, however, before this vigorous, upstart people were to have so securely established themselves as to ensure their survival in the hostile physical and cultural environment in which they had settled. All the while, they remained the political tributaries of the king of Atzcapotzalco, but by the 1360's they felt that they were ready to found a kingdom in their own right. However, because they were sorely aware that they lacked the proper "pedigree" of nobility, they requested that a prince from Culhuacán become their king. Of course, such a choice linked them dynastically to a southern rival of Atzcapotzalco and in that sense it was a brilliant tactical move as well. Thus, in 1364 Acamapichtli ascended the throne in Tenochtitlán, becoming in the process the first of the monarchs of the Aztecs.
Acamapichtli's forty year reign was largely a peaceful one, for it definitely was in the interests of the Aztecs to maintain as friendly relations as possible with the more powerful city-states that surrounded them. His successor, Huitzilíhuitl, also made an advantageous move by marrying one of the daughters of the king of Atzcapotzalco and then inducing her to implore her father to reduce the onerous tributes he had been exacting from the Aztecs, which he agreed to do.
On the death of Huitzilíhuitl in 1417, Chimalpopoca, a nephew of the king of Atzcapotzalco, became the third regent of the Aztecs. In the following year, he led his armies in the defeat of Coatlinchán, seizing the southeastern mainland of the lake for the growing Aztec city-state. However, within the decade an environmental crisis brought the Aztecs and their recently acquired relatives-by-marriage likewise to the point of blows. The expanding island city-state of Tenochtitlán was rapidly outgrowing its supply of fresh water, both for domestic consumption and for irrigating the chinampas on which its food was grown. Whether the request for help which they addressed to the rulers of Atzcapotzalco was rudely phrased or not, the latter used this as an excuse to move against what they now perceived was an alarmingly expanding rival. Secret emissaries were sent into the Aztec capital, and in 1426 both the king Chimalpopoca and his son were assassinated. This treacherous act was followed by an economic blockade of the island towns that together with the increasingly desperate water supply problem obliged the Aztecs to react with violence.
What ensued depends on whose account one wishes to believe, that of the Aztecs or that of their confederates, the nearby city-states of Tacuba and Texcoco. According to the Aztec version, they alone resisted the attacks of Atzcapotzalco and finally rose up to conquer their oppressive neighbor in 1428. Tacuba and Texcoco, on the other hand, argued that it was their alliance with the Aztecs that ultimately turned the tables on Atzcapotzalco. In any event, what is certain is that, following the election of Itzcóatl, the son of Acamapichtli, as king and the establishment of a supreme council of advisors, the Aztec state was launched upon an entirely new course of action from that time forward. Although the council included the first Montezuma (Motecuhzoma Ilhuicamina), a son of Huitzilíhuitl; Nezahualcóyotl, the poet-king of Texcoco; and Tlacaélel, another son of Huitzilíhuitl, it was the latter more than any other single individual who came to shape the destiny of the Aztec people.
For the better part of the next fifty years, three different kings occupied the Aztec throne, but throughout this entire time the real power resided with the royal counselor, Tlacaélel. At his direction, Itzcóatl began a series of reforms granting titles to the nobles and redistributing landholdings to enhance their status. Perhaps Tlacaélel's chief contribution was to forge a "historic conscience" among the Aztecs by burning the books of conquered peoples and the old accounts of his own people. He rewrote history to exalt the origins of the Aztecs and to establish a genealogical link with the Toltecs. He elevated Coatlicue, the hideous mother of Huitzilopochtli, the war god, to a special position of honor in the Aztec pantheon, and gave a new interpretation to the Aztecs' religious philosophy. The present world of "the fifth sun" had begun, he argued, with the sacrifice of the gods, especially of Quetzalcóatl, at Teotihuacán. Thus, if the gods had sacrificed themselves so the sun would move and man could live, then man should sacrifice himself so that the sun could live. This, he maintained, was the only way to postpone the final cataclysm. For Tlacaélel, war was not alone a tool of conquest, subjugation, and exploitive tribute acquisition, but also a means of ensuring a continuous supply of human victims for the sacrificial altars of the Aztec temples. He not only planned and carried out the first military campaigns of the Aztecs, securing control over the Valley of Mexico but he also launched the so-called "flower wars" whose divine mission it was, in alliance with the war god Huitzilopochtli, to subjugate all other peoples and nations in order to preserve the world. As the champions of such a noble cause, he assured the Aztecs that they would be invincible in battle.
When Itzcóatl died in 1440, Motecuhzoma Ilhuicamina succeeded him on the throne. Although the kingship was first offered to Motecuhzoma's half-brother Tlacaélel, the latter refused, no doubt because the reigns of government were already firmly in his hands. Under his guidance, the "first Montezuma" proceeded to build a great new temple in honor of their father. However, the precariousness of Tenochtitlán's food and water supply situation manifested itself again in 1454 when a famine struck the Valley of Mexico and took a heavy toll of life during the following two years. Perhaps in part to ensure that such privation would not endanger the growing city-state again, the construction of an aqueduct from Chapultepec was begun and a military campaign was launched into the Gulf coastal region that concluded with the annexation of the area around Veracruz in 1463. This lush tropical coastland provided the Aztecs with a treasure house of resources, including corn, beans, fruit, cotton, wood, and medicinal plants as well as gold dust, jewelry, precious stones, rock crystal, feathers, live birds, jaguars, seashells, and turtles. After 13 years of labor, the Chapultepec aqueduct was finally completed in 1466.
It was also during the reign of the "first Montezuma" that the Aztecs carried out an expedition that probably ranks as the closest thing to a scientific endeavor that they ever mounted. At Tlacaélel's urging, a party was sent out to look for Aztlán, the Aztecs' original homeland, and to learn if Coatlicue, the mother of the war god, was still living there. Given such a sponsor and such a questionable goal, it is small wonder that, when the expedition returned after an appropriate length of time, it could happily report that Coatlicue was indeed alive and well and that she sent her greetings!
Motecuhzoma's passing in the year 1468 once more provided Tlacaélel with an opportunity to reign as king, but again he declined, and Axayácatl, the grandson of Itzcóatl, next assumed the mantle of royal leadership. In 1473, the market center of Tlatelolco was finally and formally annexed by Tenochtitlán, having remained a separate political entity ever since its founding at the same time as the Aztec capital. It was in the same year that the great calendar stone that has since become the virtual hallmark of the Aztec civilization was also dedicated.
However, five years farther along, when the Aztec armies turned their attention westward toward Michoacán, they suffered a disastrous defeat at the hands of the Purépecha, or Tarascans. Some reports state that as many as 30,000 Aztec warriors died in this one battle on the approaches to the Purépecha capital. Undoubtedly, the Purépechas' mastery of advanced metallurgy and possession of superior weapons were of decisive importance in the campaign's outcome, but some scholars have likewise attributed the Purépecha victory to their superb military organization. Wherever the truth may lie, we do know that the defeat was extremely demoralizing to the Aztecs. It was as though the war god had abandoned them, their sacred mission to save the world had been aborted, and the myth of Aztec invincibility had been shattered. It was clear that, as a result of this single bloody disaster, the violent and short-lived Aztec Empire had already passed its psychological peak, and within a matter of months Tlacaélel is reported to have died. Axayácatl himself is said never to have recovered from this stunning blow, and after a lingering malaise of three years, he too passed away.
In 1481 Tizoc, the brother of Axayácatl was elected king but his reign was both brief and depressing. No doubt in a vainglorious attempt to rekindle Aztec pride and fervor, he began the construction of the largest temple to the war god ever undertaken, but he died in 1486 before he saw it completed. At this juncture, a third brother, Ahuízotl, was elected king, and the following year the new temple was dedicated in the presence of invited dignitaries from tributary states both far and near. (Even the king of the hated Purépechas was reputedly in attendance.) The Aztecs "pulled out all the stops" to make this event the most memorable that had ever been witnessed up until that time, for over the course of the four days that the celebration went on, it is variously reported that between 20,000 and 80,000 human victims had their hearts torn out on the sacrificial stone at the temple's top. The continuing "flower wars" with nearby Tlaxcala helped to supply many of the victims, but new military campaigns against the Huastecs to the northeast and the Zapotecs to the south also made their contributions.
If Tenochtitlán's thirst for blood was in any measure satisfied by this horrendous ceremony, that satisfaction was only temporary at best. Just as pressing, if not more so, however, was the growing city's thirst for water, and in 1499 a new aqueduct was opened into the city from the southwesterly precinct of Coyoacán. Although the entire project was carried out against the advice of some of the earlier residents of the district, the Aztecs soon found that the volume of water they had directed into the city was far too great to be satisfactorily contained. As a result, lake levels were seriously upset and the Aztec capital was flooded, apparently with a considerable loss of life. Indeed, Ahuízotl was himself injured during the inundation and after a lingering illness passed away in 1502.
Against this sobering backdrop, his son, Motecuhzoma Xocoyotzin (the "second Montezuma") assumed the throne intent on restoring whatever grandeur he could to the Aztecs. His first move was to deify himself, but in order to do this, he had to arrange for the assassination of most of the court officials who had earlier served his father, for they obviously knew too much to go along with his grandiose ambitions. When his supposed ally, Nezahualpilli, the king of Texcoco (actually a secret enemy), came forward with ominous predictions as to the imminent demise of the Aztec Empire, Montezuma was visibly shaken, and the subsequent occurrence of other mysterious omens only served to heighten his anxiety. Visions of men on horses, a smoking comet in the sky, and the destruction of the temple of Huitzilopochtli by fire unnerved him further. Worst of all was Nezahualpilli's prophecy that Quetzalcóatl would soon return to rightfully claim his kingdom, for such a warning the exiled king of Tula had himself delivered, as all the heirs of the Toltecs well knew.
When Montezuma led his people in the celebration of the "binding of the years" in 1507, he may well have doubted whether the world as he knew it would endure another 52 years. Perhaps already then the first reports were beginning to reach him of "great white houses" out upon the sea amidst the islands of the rising sun. Certainly, within a few years, these Spanish exploring vessels were being sighted off the coast of Mexico itself, and with an almost inexorable rhythm, the approach of impending doom cast its lengthening shadow over the melancholy emperor and his terror-ridden state. In what has to be one of the most remarkable coincidences of all human history, Hernán Cortés and his small band of conquistadores landed on the beach at Veracruz in the fateful Aztec year of "1 Reed" -- a year of the same name as that of Quetzalcóatl's birth and therefore one in which all Mesoamericans would have expected him to return. Paralyzed with a fear instilled by the prognostications of his own sacred calendar, the hapless Montezuma was at a loss as to how he should receive the strange white gods who had arrived on his shores. His indecision not only cost him his life, but also that of his empire, and that of Mesoamerican civilization itself.
At the time of the arrival of the Spanish on the Mesoamerican mainland, the two largest and most powerful political entities in the region were those of the Aztecs and the Tarascans, both headquartered in the high basins at the southern edge of the Mexican plateau. The Aztecs, heirs of the Nahua, or Uto-Aztecan, nomads who had pushed south out of the northern deserts in the proceeding six to seven centuries, had their capital at Tenochtitlán in the valley of Mexico, whereas the Tarascans were concentrated in the lake basins of Michoacán to the west. Spread across the Yucatán peninsula and the mountains of present-day Guatemala were the Mayas, long since past their peak as a civilization and never organized into political entities larger than city-states of relative local importance.
Contrary to general belief, the Aztecs did not constitute a monolithic empire but represented instead an alliance of three closely related tribes resident in Tenochtitlán, Texcoco, and Tlacopan. From their base in the valley of Mexico they had sent out military expeditions into the lowlands, especially toward the east and south, to acquire commodities that they could neither obtain nor produce on the plateau. These included such goods as cotton, tobacco, cacao, vanilla, jaguar skins, precious stones, incense, and colorful birds' feathers, as well as sea shells, salt, and additional supplies of basic foodstuffs, among them corn, beans, and peppers. To ensure the regular delivery of these commodities to their capital city -- the less perishable goods on a schedule of twice a year and the more perishable foodstuffs once every 80 days -- they installed military garrisons in areas of particular strategic importance. Thus, as long as such "tribute" was forthcoming, they did not insist on total political control over the areas concerned, and probably could not have succeeded in doing so had they tried. As a result, the boundaries of their "empire" were both nebulous and fluctuating -- totally dependent on the amount of coercion they could exercise at any one time. In the eastern lowlands they had one garrison stationed near the present-day town of Tuxpan to extract tribute from the Huastecas, a second at Cataxtla to guard the all-important trail between the coastal area around Veracruz and the highlands, a third at Tuxtepec to control the southern lowlands and the gateway to the Maya country, a fourth at present-day Oaxaca to keep the Zapotecs in check, and a fifth in distant Soconusco, from which such prized commodities as cacao, quetzal feathers, and rubber came.
Within the boundaries of the "Aztec empire" lay enclaves of tribal groups that had resisted domination from Tenochtitlán, at least with some degree of success. The most important of these were the Tlaxcalans, who managed to retain their "independence" at the price of the so-called "Flower Wars". The latter were annual tributes of young men and women destined for sacrifice to the Aztec gods. Indeed, to have attempted to produce and maintain such a volume of sacrificial victims within the valley of Mexico itself would have been economically and politically impossible, especially since the security of the food supply was frequently threatened by droughts and poor harvests as it was. On the other hand, by having such a ready supply of sacrificial youths of good Nahua stock in close geographic proximity, nurtured for twenty-odd years by the Tlaxcalans before delivery, was an infinitely more desirable solution for the Aztecs.
In the west the Tarascans, or Purépecha, had managed to successfully resist Aztec encroachment due to a combination of strong border fortresses, metal weapons, and superior military organization. Similarly, in the rugged mountains of the Sierra Madre del Sur the Mixtecs and Zapotecs had succeeded in holding their fortified positions against the Aztecs and on occasion had even cut off the latter's strategic trade route to Soconusco in the far south of Mexico. Nonetheless, at the time of the conquest, a total of thirty-eight distinct geographic "provinces" were regularly sending tribute to the Aztec capital, according to the list itemized in the Codex Mendoza. Although the military command resided with the nobles of Tenochtitlán, two-fifths of all booty went to this city, another two-fifths to Texcoco, and one-fifth to Tlacopan.
The trade of Tenochtitlán was conducted by a special caste of merchants known as the pochteca who originally hailed from the ward, or district, of Pochtlán on the island of Tlatelolco. The latter, located on the northwest side of Tenochtitlán, was the primary market place of the Aztec capital and was described by Cortés as being "twice the size of the market of Salamanca" back in Spain. Sahagún counted over 60 kinds of merchants engaged in trade within the market, about three-quarters of whom dealt in foodstuffs and consumables while the remainder sold manufactured goods of different types. Cacao beans served as currency, being counted out in groups of 20 and packages of 8000.
Because Mesoamerica lacked domesticated animals to serve as beasts of burden, all pre-Columbian commerce moved overland on the backs of men and along the coasts and on the few navigable watercourses by canoe. A special low caste of Aztec society, the so-called tlameme served as bearers for the merchants. They carried their heavy loads -- sometimes well over 100 pounds -- on their backs using cacaxtli, or carrying frames, supported by tumplines slung over their foreheads. Any individual caravan might well have consisted of several hundred bearers, who, taken together, could probably have carried as much as a single semi-trailer truck. Nevertheless, in view of the great distances involved, the poor quality of the trails and the variation in climates and the ruggedness of terrain through which they passed, one cannot but be impressed by the volume of goods that moved between the far-flung reaches of the Mesoamerican realm in pre-Columbian times.