Pizarro returned elated to Panama and, there, the partners formulated their plan of conquest. He then took a ship to Spain, seeking backers and royal approval. In mid-1529, he was well received at court by Charles V and showed the king Peruvian pottery, metal vessels, fine clothing, embroideries, and small worked pieces of gold, winning "the applause of all the city of Toledo."

The king and his advisers were convinced of the need to sign a deal with such experienced conquistadors as Pizarro and Almagro. At Toledo, on 26 July 1529, the queen granted Pizarro a license "to discover and conquer Peru," which is described as "a rich and fertile land, inhabited by people more reasonable than any other which has so far been discovered." The terms of the grant gave Pizarro the governorship of Peru, with the rights to explore and exploit the land on behalf of the Crown; and, in addition, a salary, to keep troops and to pay "a mayor, a doctor and an apothecary."

Nueva Corónica y Buen Gobierno
(Letter to a King)

Pizarro, in his ambition to become the sole ruler of all of Peru, later had a falling out with his partner Almagro. The two became involved in their own civil war and Almagro was killed by Pizarro's brothers. In 1541, Diego de Almagro's supporters avenged his death by killing Pizarro.