Diego de Almagro (1475 - July 8, 1538), El Adelantado, was a Spanish conquistador and a companion and rival of Francisco Pizarro. He was born at Aldea del Rey in Spain. According to another account, he was a foundling in the village from which he derived his name.

In 1525 he joined Pizarro and Hernando de Luque at Panama for the conquest of Peru.

Almagro is credited as the European discoverer of Chile. After the Spanish conquest of Peru, Almagro was dissatisfied that the country had been given to Pizarro without a major role for him. After complaining, he got Spanish royal permission to conquer the region south of Peru. His epic journey south started in Cuzco, Peru. With the help of Inca Paullu, a son of the Inca ruler Huayna Capac, he led his men over the Andes mountains, at the latitude of the current city of Copiapo , at a great cost in life. He traveled further south to the Aconcagua river, where hostile Mapuche Indians forced him to turn back north, without the treasure and riches he had hoped to find. On his voyage north he encountered the Atacama desert, where lack of water and food also took their toll. He never founded a city in the territory of (what is now) Chile.

Upon his return to Peru in 1536, Almagro was bitter and eager to claim the riches of the city of Cuzco for himself. In the previous year, the Inca Manco had briefly recaptured the royal city and weakened the Spanish hold in the Sacred Valley. Hoping to enlist the help of the Inca, Almagro offered Manco Inca a pardon on behalf of the Spanish government. Manco Inca never officially joined Almagro in his attack on Cuzco. However, most of Hernando Pizarro 's army marched into the Andes in pursuit of Manco Inca, allowing Almagro's men to claim the city for themselves.

Pizarro defeated and captured Almagro at the Battle of Las Salinas (near Cuzco) in April 1538. Almagro was executed three months later. His men then turned against Francisco Pizarro and killed him in Lima in 1541.

Diego de Almagro (1520-1542), son of the above, avenged his death by killing Pizzaro, but being conquered by Vaca de Castro, was himself put to death.

See also

• History of Chile
• Pedro de Valdivia
• Spanish conquest of Peru