In October 1492 Christopher Columbus, sailing for the Spanish crown, landed in the Bahamas and then reached Cuba and Hispaniola. He believed he was near Asia. Within a few decades the Taíno people of the Caribbean islands had been reduced to a remnant by forced labor, violence and disease. Spain and Portugal quickly moved to claim what lay beyond. The Treaty of Tordesillas in 1494 divided newly found lands between Spain and Portugal along a line running north to south through the Atlantic. When the Portuguese captain Pedro Álvares Cabral touched the coast of Brazil in 1500, it fell on Portugal's side, which is why Brazilians speak Portuguese today.
The fall of Tenochtitlan
In 1519 Hernán Cortés landed on the Gulf coast of Mexico with about 500 men. He did not conquer the Mexica alone. Many subject peoples resented Mexica tribute, and the Tlaxcalans, longtime enemies of the Mexica, became Cortés's most important allies, sending tens of thousands of warriors. Communication depended on Malintzin, a Nahua woman who interpreted for Cortés after being given to the Spaniards as a slave; Spaniards called her Doña Marina and later Mexicans called her La Malinche, a name that came to mean betrayal, though many now see her as a survivor with few choices. The emperor Moctezuma received the Spaniards in the capital and was soon held hostage. He died in 1520 amid an uprising that drove the Spaniards out. Then smallpox swept the city, killing huge numbers, including Moctezuma's successor. After a long siege by Spaniards and their native allies, Tenochtitlan fell in August 1521.
A famous story says Moctezuma believed Cortés was the returning god Quetzalcoatl. Many historians now doubt it, because the story appears mostly in sources from after the conquest, when both Spaniards and some Nahua writers had reasons to explain defeat as fate.
The fall of the Inca
Francisco Pizarro reached Peru at a moment of crisis. An epidemic, probably smallpox, had killed the Inca ruler, and his sons Atahualpa and Huáscar fought a civil war over the throne. Atahualpa had just won when, in November 1532, Pizarro's small force ambushed him at Cajamarca. Atahualpa offered a room filled with gold and silver as ransom; the Spaniards took it and executed him anyway in 1533. Inca resistance continued from the mountains of Vilcabamba until 1572.
Why so few conquered so many
Older accounts credited steel, guns, horses and supposed European superiority. Most historians now stress a mix of causes: native allies who supplied most of the soldiers, the political splits within each empire, Spanish ruthlessness, and above all disease. The conquest looked less like a few hundred Spaniards defeating millions and more like a civil war that Spaniards steered and then took over.
Spaniards also arrived with a ready-made legal script. Before attacking, commanders were supposed to read aloud the Requerimiento, a document in Spanish demanding that native people accept the authority of the pope and the Spanish king or face war and enslavement. It was often read to empty beaches or to people who could not understand a word of it, yet it let conquerors claim their wars were lawful. Critics in Spain mocked it even at the time.
The Columbian exchange
The historian Alfred Crosby coined the term "Columbian exchange" in 1972 for the transfer of plants, animals and germs between the hemispheres. Horses, cattle, pigs, wheat and sugarcane crossed west. Maize, potatoes, tomatoes, cacao, chili peppers and cassava crossed east, where they fed population growth in Europe, Africa and Asia. The deadliest cargo was invisible. Native Americans had no immunity to smallpox, measles and influenza, and epidemic diseases such as smallpox killed most of the indigenous people who died in the century after contact. Estimates vary, but many scholars think the population of central Mexico fell by around 90 percent within a hundred years. Forced labor and war made the epidemics worse by weakening and scattering communities.
Silver bound the new empire to the world. Huge deposits were found at Potosí in the Andes in 1545 and at Zacatecas in Mexico soon after. American silver paid for Spain's wars, flowed to Europe, and was carried by the Manila galleons across the Pacific to China, making the Americas part of the first truly global economy.
Worked example: two accounts of one siege
Cortés described the conquest in letters to the emperor Charles V, written to win royal favor. He presented himself as a loyal servant overcoming impossible odds, and he played down his own allies. The Nahua account in Book 12 of the Florentine Codex, gathered a generation later, tells of omens, of the smallpox that left people too weak to move, and of the grief of a city whose canals were choked with the dead. Neither source is neutral. Cortés needed glory, and the Nahua elders spoke to a Spanish friar under colonial rule. Yet together they show what neither shows alone: that the city fell to disease and to a coalition of its own neighbors as much as to Spanish arms, and that the people who lived through it understood it as the end of a world.