Mexico City

The history of Mexico City stretches back to its founding ca. 1325 C.E as the Mexica city-state of Tenochtitlan, which evolved into the senior partner of the Aztec Triple Alliance that dominated central Mexico immediately prior to the Spanish conquest of 1519–1521. At its height, Tenochtitlan had enormous temples and palaces, a huge ceremonial center, and residences of political, religious, military, and merchants. Its population was estimated at least 100,000 and perhaps as high as 200,000 in 1519 when the Spaniards first saw it. During the final stage of the Spanish conquest of the Aztec Empire, Spanish forces and their indigenous allies besieged and razed Tenochtitlan. Because it was strategically and politically important, invader Hernán Cortés founded the Spanish colonial capital of Mexico City on its ruins, becoming the center of Spanish colonial power. Following Mexican independence from Spain in 1821, Mexico City became the capital of the sovereign nation, remaining its largest and most important city to the present day.

Beginning in 1521, the Aztec ceremonial and political center was rebuilt as the city's main square, the Plaza Mayor, usually called the Zócalo. Some of the oldest structures in Mexico City date from the early conquest era. Many colonial-era buildings remain standing and have been re-purposed as government buildings and museums. As the seats of the Viceroyalty of New Spain and the Archbishopric of New Spain, Mexico City was the center not only of political and religious institutions but also of Mexico's economic activity and the residence of Spanish colonial elites (1521–1821). Great merchant houses linked to Spain were located here, and the economic elites whose properties were often elsewhere in New Spain also lived in the capital. The concentration of mansions and palaces in what is now the Mexico City historic center led it to be nicknamed the "City of Palaces", a sobriquet often attributed, perhaps erroneously, to great savant Alexander von Humboldt.

It was also a major educational center: the University of Mexico was founded in 1553 as part of the complex of the Plaza Mayor but is now located in the south of the capital.