The Valley of Mexico has drawn people from Mesoamerica attracted by its abundant sources of water, easy communication, and plentiful game and vegetation, throughout its long history of human habitation.

The valley is a corridor through which many migrating groups pass and sometimes settle.

During the pre-Columbian era, the valley is in constant turmoil except when central authority and political hegemony exist.

The last nomadic arrivals in the valley are the Mexica, more commonly known as the Aztec.

Although recent linguistic and archaeological work suggests the Aztec may have come from northwest Mexico, their origins are obscure.

According to legend, the Aztec came from Aztlan, a mythical place to the north of the Valley of Mexico around 1100.

They are said to have made their way to the valley guided by the chirps of their sun and war god Huitzilopichtli (meaning "hummingbird on the left").

The inhabitants of the valley view the new arrivals with suspicion and try to prevent their settlement.