Hernán Cortés, the Spanish conqueror of Mexico, had the most Native American slaves of anyone in the world:
"Hernán Cortés died a disappointed man. After subjugating the [Aztecs], he was awarded a title -- Marquis of the Valley of Oaxaca -- and given his choice of real estate in the lands he had conquered. He chose six spreads in central and southern Mexico: 7,700 square miles in total, an expanse the size of El Salvador. The biggest chunk, 2,200 square miles of temperate plains south of Mexico City, was where he built his thickwalled, castle-like home. An opulent place, it had no less than twenty-two tapestries, each at least fifteen feet wide; the conqueror, something of a dandy, liked to roam about his tapestries in brocaded velvet jackets and pearl-studded dressing gowns.
"Having acquired his property, Cortés threw himself with characteristic energy into a series of entrepreneurial ventures: digging silver mines; establishing cattle ranches and hog farms; panning for gold; opening a shipyard on the Pacific coast; creating a kind of shopping mall in central Mexico City; growing maize, beans, and Garrido's wheat; lending money, goods, livestock, and slaves to entrepreneurs and adventurers in return for a share of the profits; importing silkworms (and mulberry trees to feed them); and raising big stone structures as monuments to himself Sugarcane, which he began growing in 1523, was high on his list.
"Cortés might have succeeded at these enterprises if he had paid attention to them. Instead he kept looking for new kingdoms to vanquish. He marched into Guatemala. He schemed to send ships to Peru. He went to the Pacific and nearly killed himself looking for a route to China. All the while, he flagrantly disobeyed orders. Eventually he ran out of his own money and other people's patience. He returned to Spain in 1540, hoping to obtain more royal favors and positions for himself and his friends. Cortes followed the king from place to place, seeking an audience. Carlos V refused to see him. The heartbroken conquistador was unable to fathom why the sovereign might worry about creating a powerful new aristocracy of unreliable, impulsive men of action. The story, told by Voltaire but surely apocryphal, is that at one point Cortés bullied his way onto the emperor's carriage. Carlos V, annoyed, asked who he was. 'It is he,' Cortes supposedly said, 'who has given you more states than your ancestors left you cities.'
"His timing was dreadful. As he followed the court, the king was talking with Bartolomé de las Casas, a fiery Dominican priest who had just completed Brief Account of the Destruction of the Indies, an indictment of Spanish conduct that remains a landmark both in the history of human-rights activism and in the literature of sustained invective. Reading his first draft before the shocked court, Las Casas branded the conquest of Mexico as 'the climax of injustice and violence and tyranny committed against the Indians.' He denounced Indian slavery as 'torments even harder to endure and longer lasting than the torments of those who are put to the sword.' Troubled by Las Casas's lurid descriptions of cruelties committed in the name of Spain, Carlos V had asked his council of advisors to investigate the nation's policies toward Indians.
"As the king surely knew, the Spanish monarchy had been struggling to define its Indian policy since before he was born. His grandparents, King Fernando and Queen Isabel, had been stunned when Colón informed them that they now ruled over multitudes of people whose very existence had been previously unsuspected. The monarchs, devout Christians, worried that the conquest could not be justified in the eyes of God. Colon's new lands had the potential of enriching Spain, an outcome they of course viewed as highly desirable. But obtaining the wealth of the Americas would involve subjugating people who had committed no offense against Spain.
"As Fernando and Isabel saw it, Indian lands were not like the Islamic empires whom they and their royal ancestors had fought for centuries. Muslim troops, in their view, could be legitimately enslaved -- they had conquered most of Spain, exploited Spanish people, and, by embracing Islam, rejected Christianity. (For similar reasons, the Islamic empires freely enslaved Spanish POWs.) Most Indians, by contrast, had done no wrong to Spaniards. Because American natives had never heard of Christianity, they could not have turned away from it. In 1493, Pope Alexander VI resolved this dilemma of conscience. He awarded the sovereigns 'full, free and complete power, authority, and jurisdiction' over the Taino of Hispaniola if they sent 'prudent and God-fearing men, learned, skilled, and proven, to instruct [them] in the Catholic faith.' Conquest was acceptable if done for the purpose of bringing the conquered to salvation.