Here is the full list of all 35 Age of Civilizations II achievements.
Create 50 unions
Create 25 unions
Join 50 alliances
Form Ottoman Empire
Form Russian Empire
Create 50 vassals
Create 10 unions
Form Italy
Join 25 alliances
Create 20 vassals
Form Austrian Empire
Form Australia-Hungary
Join 10 alliances
Create 5 vassals
Create a vassal
Capture 1500 provinces
Create 5 unions
Create union
Join 5 alliances
Form Japan
Adopt the ideology of the City State
Adopt the ideology of democracy
Adopt the Monarchy government
Adopt the ideology of Communism
Adopt Republic ideology
Adopt the Horde ideology
Adopt Fascism ideology
Capture 750 provinces
Capture 500 provinces
Capture 300 provinces
Join alliance
Capture 150 provinces
Capture 75 provinces
Capture 30 provinces
Capture 10 provinces