Acamapichtli

The ruling house of Tenochtitlan traced its legitimacy to Acamapichtli, elected around 1376 as the first tlatoani, or dynastic ruler, of the Mexica. According to traditions written down after the Spanish conquest, the Mexica — then a tributary people recently settled on a marshy island in Lake Texcoco — sought a ruler connected to Culhuacan, whose nobility claimed descent from the Toltecs. Acamapichtli, described as the son of a Mexica father and a Culhua noblewoman, satisfied that requirement, and his accession attached the young city to the older dynastic networks of the Valley of Mexico.

The dates assigned to his life — birth around 1355, accession in 1376, death in 1395 — derive from colonial-era chronicles and pictorial annals whose year counts frequently disagree, and they are best treated as approximate. Throughout his reign Tenochtitlan remained subject to the Tepanec state of Azcapotzalco. Mexica warriors served in Tepanec campaigns against Chalco, Xochimilco, Cuauhnahuac, and other towns of the lake basin and the lands to the south, gaining military experience while their city continued to pay tribute to the Tepanec ruler Tezozomoc.

Within Tenochtitlan, the sources associate Acamapichtli with the expansion of chinampa agriculture, the digging of canals, the building of modest temples, and the first formal organization of Mexica government. His marriage policy proved as consequential as any campaign. In addition to his principal wife Ilancueitl, a noblewoman of Culhuacan, he is said to have taken a wife from each of the city's calpulli, or ward groups, and the sons of these unions formed the core of the later Mexica nobility.

Every subsequent tlatoani of Tenochtitlan descended from him. His son Huitzilihuitl succeeded him around 1396, and another son, Itzcoatl — born, the chronicles relate, to a woman of humble rank — became the fourth tlatoani in 1427 and the architect of Mexica independence from Azcapotzalco. The transition after Acamapichtli's death in 1395 took the form of an election among the royal kin rather than automatic inheritance, establishing the pattern by which later rulers of Tenochtitlan were chosen from among the sons, brothers, and nephews of previous tlatoque rather than by strict primogeniture.