Cortés went (1504) first to Hispaniola and later (1511) accompanied Diego de Velázquez to Cuba. In 1518 he was chosen to lead an expedition to Mexico. Although Velázquez later sought to recall his commission, Cortés sailed in Feb., 1519. In Yucatán he rescued a Spaniard who had learned the Mayan language; after a victory over the native people of Tabasco, Cortés acquired the services of a female slave Malinche—baptized Marina—who knew both Maya and Aztec. Having proceeded up the coast, Cortés founded Villa Rica de la Vera Cruz and was chosen captain general by the cabildo; thus he discarded Velázquez's authority and became responsible only to Charles V.
Cortés, learning that the Aztec empire of Montezuma was honeycombed with dissension, assumed the role of deliverer and rallied the coastal Totonacs to his standard; he also began negotiations with Montezuma. Scuttling his ships to prevent the return of any Velázquez sympathizers to Cuba, he began his famous march to Tenochtitlán (modern Mexico City), capital of the Aztec empire. He defeated the Tlaxcalan warriors and then formed an alliance with the so-called republic of Tlaxcala; practically destroyed Cholula; and arrived at Tenochtitlán in Nov., 1519. There the superstitious Montezuma received the Spanish as descendants of the god Quetzalcoatl. Cortés seized his opportunity, took Montezuma hostage, and attempted to govern through him.
In the spring of 1520, Cortés went to the coast, where he defeated a force under Pánfilo de Narváez. Pedro de Alvarado, left in command, impetuously massacred many Aztecs, and soon after Cortés's return the Aztecs besieged the Spanish. In the ensuing battle, Montezuma was killed. The Spanish, seeking safety in flight, fought their way out of the city with heavy losses on the noche triste [sad night] (June 30, 1520). Still in retreat, they defeated an Aztec army at Otumba and retired to Tlaxcala.
The next year Cortés attacked the capital, and after a three-month siege Tenochtitlán fell (Aug. 13, 1521). With it fell the Aztec empire. As captain general, Cortés extended the conquest by sending expeditions over most of Mexico and into N Central America. In 1524-26, Cortés himself went to Honduras, killing Cuauhtémoc, the Aztec emperor, in the course of the expedition.
In Cortés's absence his enemies at home gradually triumphed, and after his return his power was made more fictitious than real by the audiencia. Although on his visit to Spain (1528-30) Cortés was made marqués del Valle de Oaxaca, Charles V refused to name him governor. Returning to Mexico, he vainly sent out maritime expeditions, frustrated more than once by Nuño de Guzmán. Subsequently he quarreled with the viceroy, Antonio de Mendoza, and in 1540 he again sought justice in Spain. There, neglected by the court, he died.
The best-known contemporary account of the conquest is that of Bernal Díaz del Castillo. See the letters of Cortés (tr. by F. A. MacNutt, 1908); W. H. Prescott, Conquest of Mexico (1937); H. Thomas, Conquest: Montezuma, Cortés, and the Fall of Old Mexico (1994); studies by S. de Madariaga (1942, repr. 1969) and H. R. Wagner (1944, repr. 1969).