The Tepanec War Ends Mexica Subjugation
A succession crisis in Azcapotzalco turns former subjects into conquerors
Quick facts
- Losing power
- Azcapotzalco, under Maxtla
- Winning coalition
- Tenochtitlan, Texcoco, Tlacopan
- Mexica ruler
- Itzcoatl
- Result
- Tepanec power broken, alliance formed 1428-1430
What happened
When Tezozomoc died, his son Maxtla seized the Tepanec throne and moved against the very allies who had helped Azcapotzalco dominate the valley, blockading Tenochtitlan and raising its tribute demands under the new Mexica ruler Itzcoatl, while forcing Texcoco's king Nezahualcoyotl into exile. Rather than accept renewed subjugation, Tenochtitlan, Texcoco, and the smaller city of Tlacopan, joined for a time by Huexotzinco, went to war against Azcapotzalco in 1427. The coalition defeated the Tepanec the following year and destroyed Azcapotzalco as an independent power. History Crunch's summary of the alliance describes Huexotzinco withdrawing from the coalition after the victory, leaving Tenochtitlan, Texcoco, and Tlacopan to formalize their partnership.
Why it matters
This war ended nearly a century of Mexica subordination in a single campaign and put Tenochtitlan on equal footing with the region's other major power, Texcoco. It set the stage for the formal alliance that followed within months and reshaped the entire Valley of Mexico's balance of power.
How we know
The Tepanec War is described consistently across the major Nahua chronicles compiled after the conquest, including the accounts used to reconstruct Itzcoatl's and Nezahualcoyotl's roles in the conflict.
Sources
- History Crunch. Aztec Triple Alliance: A Detailed Summary · General sourcehistorycrunch.com · Cited as a "reference" source (no stronger domain match). · Link is live and its text matches the event's key terms (Jul 2026)
- World History Encyclopedia. Aztec Civilization · Reputable sourceworldhistory.org · The domain "worldhistory.org" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
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