The Triple Alliance period begins with the death of Tezozomoc in 1427.
Tezozomoc bequeaths the Tepanec kingdom, today’s Azcapotzalco to his sons Tayatzin and Maxtla. Maxtla is believed to have later poisoned Tayatzin. The kingdom at the time extended as far south as Coyoacán and Tizapan.
Itzcoatl—the “Obsidian Serpent” who lived from 1380 until 1440—reigns as tlatoani of Tenochtitlan.
Maxtla, though, is soon overthrown by the Aztec Triple Alliance, representing the Mexica of Tenochtitlan, the Acolhua people of Texcoco, the remaining Tepanec people of Tlacopan. Tlacopan was the dominant Tepanec city, but a much weaker partner within the alliance than were Tenochtitlan and Texcoco.
Nezahualcoyōtl, (born April 28, 1402) only the most notable of the Triple-Alliance leaders, reigns over Texcoco, in a period remembered for his poetry and his aversion to blood sacrifice.
The town of Zapotitlán is founded on the southern slopes of the Xaltepec volcano in what is today Iztapalapa. The Tlatelolco people, as a reward for assisting in the conquest over the Tepanec people, receive increased fishing rights. These included mainland territories that would later become San Juan de Aragón. The award also included the island today called Peñón de los baños.
Ahuitzotl’s celebrated reign as tlatoani leads to one of the greatest expansions of Mexica power. He is succeeded upon his death by Moctezuma II in 1502.
Arrival of the Spaniards: The Mexica leader, Moctezuma Xocoyotzin, meets with Hernán Cortés on November 8. The meeting is said to have taken place near the present day Hospital de Jesus.
On August 13, México-Tenochtitlan falls to the invading Spanish army.