Founding of Tenochtitlan in Mexica tradition

The story of the founding is known from Mexica traditions written down after the Spanish conquest. Expelled from Chapultepec in 1299, the Mexica had lived as vassals of Culhuacan at Tizapan; after a clash with the Culhua they fled to a small island on the western side of Lake Texcoco. There, the tradition says, they saw the sign promised by Huitzilopochtli — an eagle on a prickly-pear cactus. In early images, such as the Codex Mendoza of about 1541, whose history of the Mexica runs from the founding in 1325 to 1521, the eagle stands on the cactus without a snake (on the pre-conquest Teocalli of the Sacred War it holds the war glyph atl-tlachinolli); the eagle devouring a snake, now on the coat of arms of Mexico, first appears in later versions — Diego Durán drew it in 1581. The name Tenochtitlan is usually explained as ‘among the prickly pears growing on rocks’, or derived from Tenoch, a leader of the Mexica at the time whose historicity is debated.

The Crónica Mexicayotl and the Annals of Tlatelolco give the year 2 House, 1325, but other sources place the founding in 1318, between 1314 and 1332, or in 1327, and some authors have argued for 1345 or the 1360s; most historians accept 1325. The day of 13 March 1325, celebrated in Mexico, appears in no source and follows from no calendar calculation — it was adopted as an official anniversary in the 20th century. Archaeology suggests that the island was inhabited before the traditional date. According to the chronicles, a dissident group of Mexica founded Tlatelolco on the northern part of the island in 1337 — thirteen years later by the chronicles’ count — although a structure found at Tlatelolco in 2007 may be older still.

The first temple to Huitzilopochtli, raised after the founding in earth and perishable wood, was the first of seven successive stages of the Great Temple. For decades the Mexica remained a minor people serving more powerful neighbours: they were tributaries of the Tepanec city of Azcapotzalco, in whose domain the island lay — by 1375 at the latest — and in 1376 they took as their first tlatoani Acamapichtli, a grandson of a ruler of Culhuacan, whose dynasty claimed Toltec descent. Only with the Triple Alliance of 1428 did Tenochtitlan become the capital of an empire.