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