Escalating Tensions Between Azcapotzalco and Tenochtitlan

Timeline

1. c. 1370Azcapotzalco · Valley of MexicoAfter the death of Azcapotzalco's ruler Acolnahuacatz, his son Tezozomoc (about twenty-three years old) succeeded as tlatoani. The Tepanec empire entered its most flourishing phase, and its control policy toward the valley's city-states grew harsher and more expansionist.
2. c. 1370Tenochtitlan · Valley of MexicoThe Mexica of Tenochtitlan and Tlatelolco remained direct vassals of Azcapotzalco, required to pay regular tribute and provide military service. Tezozomoc, through resident overlord representatives and marriage diplomacy, tightened constraints on the Mexica city-states' internal affairs and external actions while maintaining the vassal order.
3. c. 1370Valley of Mexico · Valley of MexicoTezozomoc began to call on Mexica warriors more frequently for foreign campaigns; the Mexica accumulated strength and prestige in war but gained no corresponding political autonomy. The tension between the overlord's reliance and the vassal's constraint grew increasingly evident, and the standoff between the two cities deepened beneath a surface of cooperation.