In 1525 he joined Pizarro and Hernando de Luque at Panama in a scheme for the conquest of Peru. He was executed by order of Pizarro in 1538 in consequence of a dispute as to their respective territories. His men then turned against Pizarro and killed him in 1541.
Based on an article from 1911 Encyclopedia Britannica.
Almargo is credited as the discoverer of Chile. After the conquest of Peru, Almagro was dissatisfied that the country had been given to Pizarro without a major role for him. After complaining, he got permission to conquer the region south of Peru. He made an epic journey starting in Cuzco, Peru to the country south of Peru. He lead his men over the Andes mountain range, at the Latitude of the current city of Copiapo, at a great cost in life. Once on the other side, He continued south until the river of Aconcagua. There, under pressure from the hostile Mapuche indians he turned back north. On his voyage north he incountered the Atacama desert, where lack of water again took its toll. He never founded a city in the territory of (what is now) Chile.