The Mexica origin story is shrouded in myth and legend and full of propaganda and self-aggrandizing anecdotes - not unlike the origin stories of other civilizations around the world, including ours. They saw themselves – and just as importantly, they hoped others would see them – as underdogs that we looked down upon by their more civilized neighbors, and who, through their ferocious warriors and protection from their god Huitzilopochtli, entered the valley of Mexico as nomads and turned a few swampy islands no one wanted in the middle of the lake into a glorious city and the center of a massive empire in under 200 years.

The history is more complicated than that, of course. The Mexica had to be vicious warriors just to survive. It’s how they initially got the other Aztec peoples to accept them, not as equals, but as good soldiers who proved valuable as mercenaries in their wars with each other. Once the Mexica were able to settle down and build their own Altepetl, their own City-State, out on a pair of islands off the western shores of Lake Texcoco, they had to learn to be great traders and great builders just to make their city habitable.

The Mexica founded Tenochtitlan sometime between 1325 and 1345, and it would take them decades to master the logistical, political, and civil engineering challenges their island city presented. To solve the problem of limited land for farming and housing, they built artificial islands that were anchored to the shallow lake bed. To protect the freshwater around the city from being contaminated by the brackish water from other parts of the lake, they built a long dam made of wooden frames filled with stone and earth. They also engineered the dam with gates to control the water level around the city and eliminate the threat of seasonal floods. And they eventually built long causeways connecting the islands of the city with the cities on the lakeshore to the north, west and south.

Internal tensions led a group of Mexica, the Tlatelolca, to break off and form their own city within the larger metroplex of Tenochtitlan. Tlatelolco’s central market would develop into the massive trading hub of the entire Aztec world, and it made both groups of Mexica extremely wealthy, And so apart from some periods of tension, they remained closely linked physically and culturally, acting like one big city in all the ways that really mattered, though both did have their own kings and nobility and temples and other institutions.

By 1425, the Mexica were secure in their island city and the other Aztecs had finally accepted the reality of their existence. They weren’t yet respected in the way they would have liked, but they were now at least players in the region who had to be considered by the other city-states. Little did they know, however, that 1425 would be a turning point for them and set them on a trajectory to greatness.