List of confederations

This is an incomplete attempt at an exhaustive list of confederations.

Confederations of states
Includes confederations of confederations.

Greek city state leagues
The Ancient Greeks formed many Leagues which often acted as confederations and alliances usually to combat a common enemy, These polities would often be known as symmachia and koinon.

Supranational 'confederations'
A supranational union is a supranational polity which lies somewhere between a confederation that is an association of sovereign states and a federation that is a single sovereign state.