Pizarro, the name of two Spanish half brothers who were soldiers and adventurers in the New World.

Francisco Pizarro

(1471–1541) discovered and conquered the Inca Empire of Peru. He was the illegitimate son of an army officer, and never learned to read and write. Pizarro enlisted in the army and by 1509 had reached America. In 1513 he was a subordinate commander in Balboa's expedition, the first to sight the Pacific Ocean. Later he became a rancher and trader in Panama.

Attracted by tales of enormous wealth to the south of Panama, Pizarro organized an expedition in 1524. His partners were Diego de Almagro, an adventurer like himself, and Hernando de Luque, a priest who stayed behind but provided the money. Pizarro and Almagro landed on the Pacific shores of Colombia but found no riches.

On a second voyage, 1526–28, one of Pizarro's pilots met a large Peruvian sailing raft. The gold and silver objects he saw on it confirmed the promised riches of Peru. Pizarro explored the coast and traded for gold at the Inca coastal city of Tumbes. Returning to Spain he gained support from Charles I (Charles V of the Holy Roman Empire) for a new expedition. Pizarro was promised the position of captain general of Peru for life if he could conquer the kingdom.

In January, 1531, Pizarro sailed from Panama on his third and final expedition. He had three ships, 180 men, 27 horses, and a few pieces of artillery. At Tumbes he learned that the Inca empire had been weakened by a succession struggle. Atahualpa, an illegitimate son of the late emperor Huayna Capac, had seized power from Huáscar, the legal ruler. Pizarro set out for Atahualpa's headquarters at Cajamarca, across the Andes Mountains. The Spanish were not challenged, but their journey over the mountains was difficult.

Late in 1532 Pizarro and his men obtained an interview with Atahualpa. When the emperor refused to become a Christian and a vassal of Spain, the Spanish routed his unarmed guard and took him prisoner. The Incan army was terrified by the horses, firearms, and steel swords of the strangers. To ransom their king, the Incas filled one room with gold objects and another with silver; nevertheless Pizarro had Atahualpa killed. The Spanish reached Cuzco, the Inca capital, in 1533, and plundered it. Lima, near the coast, was founded by Pizarro as the new capital in 1535.

Pizarro was made a marquis by King Charles. Almagro, his partner, received the governorship of what is now Chile and southern Bolivia. Embittered because his provinces were poor, Almagro began a war with Pizarro. Meanwhile, the Incas rebelled. Pizarro managed to defeat both enemies and had Almagro put to death in 1538. He was killed by Almagro's supporters in 1541.

Gonzalo Pizarro

(1506?–1548) accompanied his half brother in the conquest of Peru. He was made governor of Quito (now in Ecuador) in 1539. Gonzalo began an expedition eastward in 1540 to explore the interior of South America. A shortage of supplies caused most of the expedition to turn back, but some of the men continued; led by Francisco de Orellana, they became the first Europeans to travel the length of the Amazon River. In 1544 Gonzalo occupied Lima and proclaimed himself viceroy (governor) of Peru. He killed the legal viceroy in 1546. Pedro de la Gasca was sent by the Spanish king to retake Peru; he defeated Gonzalo and executed him for treason in 1548.