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