Introduction. The "slaughter'd Saints" of line 1 refer to the Waldensians or Vaudois, a proto-protestant sect that had inhabited the mountainous Piedmont region since the late 12th century. Many English prostestants, perhaps even Milton, regarded the sect as a sort of remnant of first-century Christianity unsullied by Roman superstitition and corruption. Although technically excommunicate, this sect enjoyed some toleration, but in 1532 they allied themselves with Calvinists in France and Switzerland. Thus official tolerance for protestantism, formalized in the January Edict of 1561, applied to them so long as they confined themselves to certian designated remote regions.

In 1655 the Duke of Savoy enforced once again, with an army, the provision that Waldensians return to the remote mountain regions. Claiming they met widespread resistance, the army proceeded on the 24th of April, 1655, to massacre them, men women and children. Reports of atrocities committed by the Duke's army reached England and aroused the indignation of Cromwell's government. Milton was commissioned to write state letters communicating England's shock and its official, if disingenuous, disinclination to believe the French could be so brutal (see the letter he wrote on Cromwell's behalf to "Lewis, King of France" on July 29, 1655 as printed in Letters of State [1694] 153-57). He also composed this sonnet, presumably around the same time.

Sonnets 18,19,20,21,and 23 were numbered XV., XVI., XVII., XVIII., and XIX., respectively in Poems (1673). I have printed them here as they are found in 1673 except for the numbers.

Avenge O Lord. See Luke 18:7 and Revelation 6:10.

slaughter'd Saints. This poem protests the violent termination of freedom of worship for a Protestant sect known as the Waldensians on April 24, 1655.

worship't Stocks and Stones. See the condemnation of idolatrous leaders in Jeremiah 2:27.

thy book. The book of God's judgments is mentioned in Exodus 32:32-3 and Revelations 5: 1.

grow/ A hunder'd-fold. The myth of Cadmus in Ovid's Metamorphoses 3.150-190 imagines that soldiers grew from the sowing of serpent's teeth. See also the parable of the sower in Matthew 13:3-8.

Mother with Infant. Cromwell's agents reported that a mother and child were thrown over a rocky cliff during the massacre of the Waldensians (Carey and Fowler 412).

sow. The word appears as "so" in 1673 and has been corrected from the Errata.

triple Tyrant. The pope sometimes wore a triple crown instead of a mitre. Elizabeth Sauer (in Milton Studies 44 [2005]) also suggests this may refer to the triple threat against European Protestants represented by Irish, French and Italian Catholic armies under the command of the Duke of Savoy in 1655.

Babylonian wo. In Sonnet 108 Petrarch refers to the Papal Court as a Babylon and "fountain of woe" (Hughes 168).