Aztec Triple Alliance

Timeline

1. c. 1428–1430Tenochtitlan · Valley of MexicoTenochtitlan joined with Texcoco and Tlacopan to defeat Azcapotzalco, establishing the framework of the Triple Alliance: Tenochtitlan held military leadership and four-tenths of the spoils, Texcoco took three-tenths, Tlacopan two-tenths, and the remaining tenth went to shared ritual and administration.
2. 1440–1450Valley of Mexico and surroundings · Valley of MexicoMontezuma I (r. 1440–1469) led allied armies beyond the valley, conquering city-states along the Veracruz coast and in Oaxaca, and establishing systems of tribute, human sacrifice, and embassies; the alliance was upgraded from a regional league to the embryo of a great empire covering much of Mesoamerica.
3. 1451–1502Territory of the Aztec Empire · MexicoThe alliance maintained the warrior class and the order of vassal city-states through mechanisms such as the 'Flower Wars,' systematically collecting grain, cloth, rare birds, and captives via the tribute roll (Matrícula de Tributos); the division of labor among the three partners was clear while the leading partner's power kept rising, forming a clearly hierarchical tributary imperial network.
4. 1519–1521Tenochtitlan · MexicoAfter the Spanish landed in 1519, the alliance's vassals defected one after another; Tenochtitlan fell in 1521, the Triple Alliance ended as a political–military entity, and the era of the Aztec Empire in Mesoamerica came to a close.