Masses
Haydn wrote Masses for the Esterházys (as opposed to Passions) because Austria is a Catholic country.
The full Mass has 5 parts: Kyrie, Gloria, Credo, Sanctus, Agnus Dei.
From 1796-1802, Haydn wrote his last 6 masses. He was reemployed by Prince Paul Esterházy to write pieces for the Princess's name day. He wrote one each summer while residing at Esterháza. He lived in Austria (Vienna) otherwise.