In 1519, the native civilizations of Mexico were invaded by Spain, and two years later in 1521, the Aztec capital of Tenochtitlan was conquered. Francisco Hernández de Córdoba explored the shores of South Mexico in 1517, followed by Juan de Grijalva in 1518. The most important of the early Conquistadores was Hernán Cortés, who entered the country in 1519 from a native coastal town which he renamed "Puerto de la Villa Rica de la Vera Cruz" (today's Veracruz). Contrary to popular opinion, Spain did not conquer all of Mexico in 1521. It would take another two centuries before that would occur, as rebellions, attacks, and wars continued against the Spanish by other native peoples.

The Aztecs, the dominant power in the country, believed (according to ancient myths)"the tradition that Quetzalcoatl would return on in "Ce-Acatl" or one-reed year. The Pre-Columbian calendar was divided into 52 year periods or cycles. Every 52nd year was a Ce-Acatl year [1467] was such a year" that the Spanish conquerors were people sent by the gods (according to orthodox scholarship), so they offered little resistance initially to the advances of the conquerors. (Ironically, Cortes does not mention the alleged "god worship" episode in his letters to King Charles V of Spain.)

Modern scholarship is beginning to question this view of events, however. Noted Aztec scholars like Ross Hassig of the University of Oklahoma have demonstrated that Quetzalcoatl was in actuality a religious order of priests during the previous Toltec era. This order of priests, under the tutelage of its leader--Ce Acatl Topiltzin Quetzalcoatl-- is famous for its exile into the eastern area of Mexico (what is now known as Yucatan). It may have been thought then, that the Spaniards were possibly of the lineage of that "Order of Quetzalcoatl," and hence, deserved serious diplomatic accommodations. They did,

Adding to the confusion is the fact that the Nahuatl language of the Aztecs is infused with terms of humility and politeness, especially for guests. Foreign ambassadors were aways treated reverently and invited into the capital of Tenochtitlan, where they experienced all the high diplomacy expected between nations. Eventually they opposed the Spanish when it became evident that they were not of the lineage of the Quetzalcoatl priests, much less gods.

After a major battle in 1519, during which the Spanish forces were defeated and sent into retreat, the Spaniards regrouped outside the Valley of Mexico. After eight months they were back, this time with an even larger contingent of native allies. By then, Spanish smallpox had ravaged the Aztec population, drastically reducing the Aztec fighting forces. The Spaniards surrounded and laid siege to the inhabitants of Tenochtitlan, the capital of the Aztec Empire, bringing about the Aztecs' total defeat in 1521. Despite their metal weapons, horses, cannons, and thousands of indigenous allies, the Spanish were unable to subdue the Mexica for seven full months. It was one of the longest continuous sieges in world history.

Three major factors contributed to Spanish victory. First, the Spanish had superior military technology, including firearms, the crossbow, iron and steel weapons, and the horse. The Spanish were further aided in their conquest by the Old World diseases (primarily smallpox) they brought with them, to which the natives had no immunity, and which became pandemic, killing large portions of the native population. Finally, the Spanish enlisted the help of various subject peoples in the Aztec Empire who saw the Spanish as a means to free themselves from Aztec rule, mainly the Tlaxcalans.

With the conquest a new ethnic group was created by the Spaniards: the mestizo, a result of the conquerors taking native women as a measure against revolt by the natives and beginning the mixing of both cultures. Quite often, rape was a factor in the reproduction of mixed-race children.

The Spanish Inquisition, and its descendant, the Mexican Inquisition, continued to operate in the Americas until Mexico declared its independence.

During the colonial period, which lasted from 1521 to 1810, Mexico was known as "Nueva España" or "New Spain", whose territories included today's Mexico, the Spanish Caribbean islands, Central America up to and including Costa Rica, and an area comprising today's southwestern United States. Most of this land was dominated by Spanish landowners and their white descendants. Europeans, in fact, totally dominated the politics and economy of colonial Mexico. Mestizos came next, and native peoples occupied the lowest rung of society.

Source: Wikipedia