According to their own legend, the mexicas came from a legendary called place Aztlán, "place of the herons", presumably located in the northwest of Mesoamerica. From there they would have left in 1111 D.C., in the search of a place where to settle. They would recognize this place indicated by Huitzilopochtli, their guardian god, where they would find an eagle posed on a nopal and devouring a snake. Almost two centuries of pilgrimage took the mexicas to find that place. An island in the lake of Texcoco. Mexico-Tenochtitlan was founded in the year 1325 D.C., city that would end up becoming in hardly one century in the most important in Mesoamerica.

Almost two centuries after its foundation, in the time of the Spanish conquest, Tenochtitlan was a great city organized in four big calpullis or neighborhoods; it was connected with the lakeside towns by means of extensive roads, it had a population of 150,000 or 200,000 inhabitants and it occupied an area of 15 square kilometers.

In 1430, the mexicas created an entity that would substitute the one that the tepanecas controlled. The new one was formed by Tenochtitlan, Tlacopan and Texcoco, and it is known as the Triple Alliance. Starting from that moment, the mexica tlatoanis (rulers) began a series of conquests which, in little less than a hundred years, would take them to dominate diverse Meso-American regions.

The mexica supremacy was founded in its extraordinary military capacity and an effective strategy of public demonstration of its might, one that included ceremonies with human sacrifices, ehre the gentlemen of the subdued towns were force to go.

In spite of this military supremacy and the power of the Triple Alliance independent dominions existed such as: Metztitlan, Tlaxcala, Cholula, Teotitlán del Camino and Yopitzinco. Special attention must be given to the tarascos, the only unbeatable enemies of the mexicas.

The destination of the products obtained by means of the tribute was diverse. They were used for the religious celebrations; for the payment of the administration of the empire; to sustain the urban populations, and to cover the expenses of the war. Another part returned for the circulation of goods by means of trade.