It was not until the arrival of the Aztecs, a mysterious tribe of people who came in from the north, that the area acquired its importance.The Aztecs migrated following an ancient legend that prophesied that they would find the site for their new city in a place where they would see a mythical vision fulfilled: an eagle eating a snake while perched atop a prickly cactus(Nopal).
Wandering from place to place, like the Jews of Israel, guided by their oracle, the Aztecs eventually came across this land, on what was then a small swampy island in Lake Tex-coco in the Valley of Mexico and in 1325, built their capital Tenochtitlan (Nahuatl name for the city) of the expanding Aztec Empire and their civilisation. The Mexican legend says that Aztecs were persuaded by their war-god Huitzilopochtli or Mexitl (from whom was derived the name Mexica or Azteca and the name adopted by its people, to settle on this swampy island.
Undeterred by the inhospitable land, they invented the chinampa system to dry the areas by dividing them in small plots, and once that achieved, they built their capital city, which stood on an artificial lagoon. The Aztec built their first temple in honour of their bloodthirsty god Huitzilopochtli, who had led them to this promised land, as Moses led the Jews of Israel. The huts were made of reeds and mud (cañas y barro) , which grew in the swampy land, and called them Xacali, which was called Jacales ( shanties of the poor peóns) by the Spaniards. Peóns were enslaved by the Spaniards to work on their haciendas and silver mines. Much of the early construction of huts was of caña y barro.
At the centre of Tenochtitlan was a large walled precinct, the focus of religious activity, containing the main temples (dedicated to Huitzilopitchli, a deity of war, sun, human sacrifice and the patron of the city of Tenochtitlan, Tlaloc the Rain God, and Quetzalcoatl, the white man, the Feathered Serpent, one of the major deities of the ancient Mexican pantheon.
Aztec and mythical Maya built stone temples, pyramids, great chambers and tombs, inscribed hieroglyphics and made artifacts. Even today the mythical civilisations of Aztec, Incas, Toltec and Maya are admired by us. The Toltec were the founders of Teotihuacan and Cholula, the historical pyramids for their worship, human and animal sacrifice, and who were termed as despotic and barbaric, uncivilised noble savages by the Spanish conquistadors.
Mexican believed that Quetzalcoatl, the "Feathered Serpent", a white man of an imposing personality and noble features, a foreigner, who had come to live with them and taught them the religion of living simple and austere life, in which the sacrifice of humans and animals was forbidden, who after living among them for more than twenty years, promising that he would one day return, mysteriously disappeared in the direction of the Rising Sun.
This belief that he would return from the east in a One Reed year led the Aztec sovereign Montezuma II to regard the Spanish conqueror Hernan Cortez and his comrades as messengers of the Sun God, welcomed them, protected them, because 1519, the year in which the Spanish landed on the Mexican coast, was a One Reed year (Aztec calendar, dating system based on the Mayan calendar).
Mexican were awed at the tall ships with white sails, which appeared on their horizon, men dressed in strange costumes and riding strange animals (Mexican had never seen horses before) and bulls pulling strange vehicles (gun carriages) and with superstitious reverence, fell at their feet.
Between 1519-1521 when Hernan Cortez invaded Mexico. the city of Tenochtitlan was besieged several times. In order to create space for their cavalry to manoeuvre, the conquistadors pulled down most of the city's buildings and thus largely destroying the city. Mexico City was built on top of the ruins of the city. During the siege, the city was ravaged by small pox which was brought to the country by the Spanish and the Aztec King Cuitlahuac, died during the siege. In 1521 the last emperor Cuauhtemoc (Guatemoc) the defender of Tenochtitlan, surrendered to the Spanish invaders. Thus ended the mighty empire of the Aztec.
In the 17th century, the Spaniards had the brilliant idea of draining the Lake but discontinued it later. In consequence, in 1629 the city of Mexico was flooded. Similar flood occurred in 1622. Many thousands poor Mexicans living in los Jacales (shanties) perished in these floods. The whole city has been gradually sinking since then.