Agrippina’s son Drusus Caesar, imprisoned in Rome,…

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.

The Aztec, after much wandering and a few wars, in the early 1300s, reach the marshy islands in Lago de Texcoco (site of present-day Mexico City), where they see an eagle perching on a cactus tree and holding a snake in its beak (an image reproduced on the modern Mexican flag).

According to Aztec legend, this is a sign indicating where they should build their new capital city.

Tenochtitlan is eventually built on an island in Lago de Texcoco and gradually becomes an important center in the area.

Drinking water comes from Chapultepec hill on the mainland, and causeways connect the island to the shores of the lake.

The Aztec establish a monarchy in 1376, naming Acamapichtli as their first king.

Uxmal, ruled over by the Xiu family, had been the most powerful site in western Yucatan, and for a while in alliance with Chichén Itzá dominated all of the northern Maya area.

From some time after the beginning of the thirteenth century, major construction seems to have come to a permanent halt at Uxmal, possibly related to the fall of Uxmal's ally and the shift of power in Yucatan to Mayapan.

The Xiu move their capital to Maní, and the population of Uxmal declines.

The dense population of the Valley of Mexico meant that there was nowhere to go when the Mexica arrived in  the region as a semi-nomadic tribe.

They had first settled on Chapultepec, a hill on the west shore of Lake Texcoco, the site of numerous springs, in roughly 1248.

The Republic of Mexico and its capital, Mexico City, derive their names from the word "Mexica".

The Mexica will be the dominant partner of the Aztec Triple Alliance, which is to become the hegemon over large parts of Mesoamerica in the fourteenth, fifteenth and sixteenth centuries.

The Tepanecs, or Tepaneca, had arrived in the Valley of Mexico in the late twelfth or early thirteenth centuries.

Welcomed to the Valley of Mexico by Xolotl, the god with associations to both lightning and death, the Tepanecs, as well as the Acolhua and other tribes speaking the Nahuatl language and sharing the same general pantheon, with local and tribal variations, have settled on the west shores of Lake Texcoco.

Under their tlatoani, Acolnahuacatl, the Tepanec had taken over Azcapotzalco from the indigenous inhabitants.

Azcapotzalco and ...

…Culhuacan on the south shore are the two most powerful of the many city-states in the Valley of Mexico.

Culhuacan, by tradition founded by the Toltecs under Mixcoatl as the first Toltec city, had survived the fall of Tollan in the late twelfth century and maintained their prestige.

Others city-states of the Valley of Mexico are Chalco, …

…Tlacopan, and …

…Xochimilco.

The Xochimilcas, who had penetrated into the heart of Mesoamerica, had established the ceremonial center of Cuailama in the tenth century (today Santa Cruz Acalpixca).

A number of pre-Hispanic hieroglyphs in the nearby mountain range have been found which are believed to be related to ceremonial rituals.

Xochimilcas, whose territory includes the Xochimilco lake shore and the isles of Tláhuac and Mixquic towards the mountain range of Ajusco-Chichinauhtzin.

The Xochimilcas are the probable founders of the city of Xochimilco and inventors of the chinampa, possibly as an improvement to a technique previously introduced by the Nahuatlacas tribes.

Often referred to as "floating gardens," chinampas are stationary artificial islands that use small, rectangle-shaped areas of fertile arable land to grow crops on the shallow lake beds in the Valley of Mexico.

A second group of Aztec at Lake Texcoco settle the island of Tlatelolco, nearby the capital of Tenochtitlán, in 1358.