Diego de Almagro was born in the town of Almagro in central Spain. He was of humble origins, having been abandoned as an infant on the steps of a local church.
Little else is known of his life before 1514, the year he accompanied PEDRO ARIAS DE ÁVILA on an expedition to Panama. Almagro became associated with FRANCISCO PIZARRO, with whom he entered into a partnership for the exploration and conquest of what is now Peru. From 1524 to 1528, he explored the northwest coast of South America in conjunction with Pizarro, taking part in military campaigns against Indians. In one encounter in 1525, he was wounded and lost an eye as well as some fingers.
Almagro provided financial support for Pizarro’s 1531 expedition against the Inca Indians. In 1533, he took part in the campaign that secured Quito in present-day Ecuador. Later that year, Almagro arrived at Cajamarca, Peru, where he joined Pizarro with a force of 200 men and played an important role in the conquest of the Inca. Although he received no gold for his participation, he was granted governorship of the lands south of Cuzco.
A conflict between Almagro and Pizarro was averted when, in December 1534, Almagro was appointed governor of the newly organized Peruvian province of New Toledo and given permission to lead an expedition of conquest southward.
Almagro, with a force of about 750 Spaniards and thousands of allied Indians, left Cuzco, northwest of Lake Titicaca, in July 1535. Inspired by reports of a civilization rich in gold and other valuables, Almagro led his men southward along the central ANDES MOUNTAINS into what is now Bolivia and northern Argentina. Having set out in the midst of the South American winter season, the Spanish suffered great hardships in the severe cold of the high Andes. At the San Francisco Pass, the expedition turned westward and reached the coastal Copiapó Valley. Almagro and his men continued southward along the coastal plain of present-day Chile into the Central Valley. Along the way, they were repeatedly attacked by Araucanian Indians. One of his lieutenants, Gómez de Alvarado, explored southward to the Itata River, north of what is now the city of Concepcíon. Failing to locate an advanced civilization comparable to the Inca, Almagro decided to head back northward to Peru. The return journey took the Spanish through the Atacama Desert, along the north coast of Chile, where many died of thirst.
By early 1537, Almagro had reached Arequipa in southern Peru, and from there he recrossed the Andes to Cuzco. At Cuzco, he found the Inca, under Manco, in open revolt against the Spanish. Almagro succeeded in suppressing the uprising but became embroiled in a conflict with Francisco Pizarro and his brother HERNANDO PIZARRO over who had the right to rule Cuzco and the northern provinces of Peru. Forces under Hernando Pizarro captured Almagro at Cuzco in April 1538. He was put to death by the garrote; his body was then publicly beheaded in the town square. In 1541, Almagro’s half-Indian son, Diego, known as “the Lad,” led a campaign against the Pizarros and, in revenge for his father’s death, killed Francisco Pizarro.
Diego de Almagro’s exploration south of Peru into Chile extended Spanish domination along the west coast of South America. On his return journey, he led his men on the first European crossing of the Atacama Desert.