What it was
Formed in 1428 after the overthrow of the Tepanec city of Azcapotzalco, the alliance bound three altepetl (city-states) in a pact to share conquest and tribute. Tenochtitlan steadily became the leading partner.
Role
The alliance conquered a broad tribute empire across Mesoamerica, drawing goods, labor, and captives from subject peoples. It ruled through tribute and indirect control rather than a unified administration.
Fate
Resentment among tributary peoples helped the Spanish and their allies destroy the alliance in 1521. Its capital became Mexico City and the seat of New Spain.