In 1531, a group of Spaniards led by Francisco Pizarro landed on the shores of the Inca Empire, thus starting the Spanish conquest of Peru. At that time the empire was emerging from a civil war in which Atahualpa had defeated his brother Huascar to claim the title of Sapa Inca. Atahualpa underestimated the strength of the small force of Spaniards and was captured during an ambush at Cajamarca in November 1532. Pizarro ordered the execution of the emperor in July 1533, and occupied the Inca capital of Cusco four months later. To replace Atahualpa, Pizarro installed his brother Túpac Huallpa as a puppet ruler, but he died shortly afterwards. Another brother, Manco Inca, was crowned in his place. During this stage, Atahualpa's generals were the only opposition to the Spanish advance as a sizable part of the empire's population had fought on Huascar's side during the civil war and joined Pizarro against their enemies.