The Spanish conquest of the Aztec Empire was one of the most important campaigns in the Spanish colonization of the Americas. The invasion began in February 1519 and was acclaimed victorious on August 13, 1521, by a coalition army of Spanish conquistadors and Tlaxcalan warriors led by Hernan Cortes and Xicotencatl the Younger against the Aztec Empire. Hernan Cortes de Monroy y Pizarro, 1st Marquis of the Valley of Oaxaca (1485-1547) was a Spanish Conquistador. The fall of the Aztec Empire brought large portions of mainland Mexico under the rule of the King of Castile in the early 16th century. Cort矇s was part of the generation of Spanish colonizers that began the first phase of the Spanish colonization of the Americas. Cortes is identified as the third man from the front.