The Capitulación de Toledo, signed by the Spanish crown, gave Pizarro the title of governor and captain-general over the lands he would conquer in Peru. Armed with this authority, Pizarro assembled a small force that within a few years captured the Inca emperor Atahualpa, sacked Cusco, and dismantled the largest empire in the pre-Columbian Americas, reshaping South America's political and demographic future.
Francisco Pizarro was an illiterate, illegitimate son of a Spanish infantry colonel who had already spent decades in the Americas, present at Balboa's sighting of the Pacific and scraping together a modest fortune in Panama before hearing rumors of a fabulously wealthy empire to the south. He traveled to Toledo in 1528 to plead his case directly to the crown, and on March 5, 1529, Queen Isabella (acting for Charles V) signed the Capitulación de Toledo, granting him the governorship of whatever lands he could conquer, along with a cut of the plunder.
It was a contract for conquest issued on spec, remarkably casual given what followed. Pizarro returned to Panama, recruited fewer than 200 men, and sailed south into Inca territory, arriving at a moment of catastrophic vulnerability: a civil war between rival claimants Atahualpa and Huáscar had just ended, and smallpox, introduced by earlier European contact elsewhere in the Americas, had already scythed through the population.
By 1533, Pizarro's tiny force had captured and executed Atahualpa and seized Cusco, the Inca capital. The charter signed that March day set in motion the destruction of an empire of perhaps six million people and the beginning of nearly three centuries of Spanish colonial rule over the Andes.