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