A papal brief gives Portugal's king more power over the church abroad than at home

Vasco da Gama's voyage around Africa to Asia, following Columbus, forced Rome to decide in a hurry who controlled the church in newly reached lands. Pope Leo X settled it for Portugal in the brief Praecelsae Devotionis of 1514, granting the crown authority over the church overseas greater than the authority it held over the church at home. At the time there was almost no organised Catholic missionary work anywhere, so the grant may have looked harmless. It was not. For the next two centuries Lisbon used it to keep missionaries of other nations out of every coast it claimed, and Rome, which rarely admits an error, lived with a weakened version of the arrangement into the twentieth century while chipping away at it. When Italian and Spanish friars finally reached the Kongo in the seventeenth century, they got there because the Dutch had temporarily taken Angola and Spain and Portugal were at war.

By 1514 the indigenous population of Hispaniola stood at about twenty-nine thousand. Estimates of what it had been in 1492 vary widely, from a few hundred thousand to more than a million, and the disagreement among historians is genuine, turning on how much land the islanders farmed and how many people that land could feed. No figure in the range makes the fall look like anything other than a collapse inside one human lifetime. Two forces did it. The first was disease. Smallpox, influenza and measles had circulated in Eurasia and Africa for centuries and the people of the Caribbean carried no resistance to any of them. The second was the labour system. Men were sent to pan gold in river gravel and women were set to work in Spanish fields, which broke up households, stopped the planting of the cassava and maize the islands lived on, and pushed the birth rate down while it pushed deaths up. Famine follows when the farmers are somewhere else.

In 1516 the chronicler Peter Martyr described the peoples of the New World as white, setting them against black Ethiopians. The comparison did more than note complexion. It placed the two groups on a ladder, and the ladder held. When Francois Bernier made the first attempt at a formal classification of human races in 1684, he assimilated the peoples of the Americas to the white race, which his scheme treated as the normal one, and left Africans at the far end of it. By the late fifteen thirties Spanish law had declared the indigenous peoples of the Americas free in principle and vassals of the crown like Spaniards, if secondary ones, while Africans remained the only openly enslaved labour force in the Spanish empire. The legal difference and the classificatory difference held each other in place for the next three centuries. A theological scheme and a natural historical one arrived at the same ranking.

Africans were on the island from about 1500. King Ferdinand sent the first official consignment in 1510, to work the mines and the sugar. Bishop Las Casas argued for the substitution in the hope of sparing the indigenous population, and lived long enough to regret having said it. The Heinls call the result a hecatomb. The system Las Casas helped licence ran for three centuries and consumed millions of lives. Two dates inside this span matter more than the rest. By 1503 enslaved Africans were already going into the mountains and building free settlements there, which makes marronage on this island older than its sugar industry and almost as old as slavery itself. In 1518 Charles the Fifth issued a formal slaving monopoly with an annual ceiling of four thousand captives, many of them taken from the coasts of Dahomey and Guinea. Those coasts became the ancestral ground of the people who took the colony back in 1804.