Spanish conqueror and explorer and leader of antiroyal forces in Peru. Pizarro is considered by some historians to be the leader of the first genuine struggle by colonists for independence from Spanish domination in America.

A half brother of Francisco Pizarro, with whom he fought during the conquest of Peru (1531–33), Gonzalo received for his services extensive land grants and was made governor of Quito in 1539. In 1541, with 200 Spaniards, some 4,000 Indians, and numerous horses and other animals, he led an expedition into the unexplored region east of Quito. After his lieutenant, Francisco de Orellana, left him in search of provisions, Pizarro and his men waited in vain for his return. Forced to eat their dogs and horses, they finally staggered back to Quito in August 1542. Only a few Spaniards and no Indians survived the disastrous expedition.

On his return, Pizarro learned that his half brother Francisco had been assassinated in 1541 and that he had been ordered to dismiss his men. The king of Spain had promulgated new laws restricting the privileges of the conquistadores and protecting the rights of the Indians. Objecting to these edicts, the Spaniards intended to fight for their prerogatives and acclaimed Pizarro as the governor of Peru. As the leader of the antiroyal forces, he took the field against the viceroy Blasco Núñez Vela, winning the Battle of Anaquito in 1546, and against the viceroy Pedro de la Gasca in 1548. Defeated and captured by de la Gasca on April 9 of that year, Pizarro was executed the following day.