In a life of bold decisions, none was more significant for the future than Cortés’s decision to rebuild the city of Tenochtitlán-Mexico and to make it the capital of the kingdom of New Spain. The site had many serious disadvantages. It was an island, marshy and reputedly unhealthy; it produced no food of its own, except the fish caught in the lake; its drinking water had to be brought by expensive artificial means from the hills of Chapultepec, several miles away; it communicated with the mainland by causeways, and many among Cortés’s following thought that these causeways, with their easily invested bridges, would be dominated by the Indians of the mainland rather than by the island Europeans. Moreover, a large Indian population still lived on the island, lurking among the ruins of buildings which Cortés had had pulled down in order to dump the rubble in the drainage canals, to facilitate the manœuvres of his cavalry. In short, the site might well be a trap, incapable of resisting siege, and peculiarly vulnerable in its provisioning and water supply.

Cortés, though certainly aware of the economic defects of the place, overrode the objections. He believed it to be as strong a site for Europeans as for Indians. Further, he probably wished to avoid a too rapid dispersal of his followers through the land they had only partly conquered, where they might still become the victims of their new vassals, or of their own disagreements. Finally Cortés was wise enough to appreciate the prestige of Tenochtitlán, its ‘renown and importance’, as he expressed it.