The Conquistadors

In the early 1500s, Spain had a foothold in the Caribbean and an appetite for more. Out from its islands sailed the conquistadors — adventurers, soldiers and minor noblemen, hungry for gold, land and a name. Few of them were sent by armies; most paid their own way, gambling their lives on the chance of sudden riches. Ahead of them, though they did not yet know it, lay two of the largest and most sophisticated empires on Earth.

To the north, in what is now Mexico, stood the Aztec empire, ruled from Tenochtitlan — a vast city built on a lake, with causeways, canals, markets and temples that astonished the first Europeans who saw it. Far to the south, along the spine of the Andes, the Inca empire ran for more than two thousand miles, linked by stone roads and governed with remarkable order from its capital, Cusco. Each empire ruled millions. Each could field armies the conquistadors could never hope to match in numbers.

And yet the Spanish carried advantages no local army had faced before: steel swords and armour, gunpowder weapons, war dogs, and horses — animals unknown in the Americas. They also carried something more terrible still, without even knowing it: the diseases of the Old World, against which the peoples of the Americas had no defence at all.

In 1519 Hernán Cortés landed on the Mexican coast with around 500 men, sixteen horses and a few cannon. Rather than retreat, he reportedly destroyed his own ships so that no one could turn back. As he marched inland he learned the secret that would decide everything: the Aztecs were not loved by everyone they ruled. Many peoples resented them, and the city-state of Tlaxcala, after first fighting the Spanish, became their most important ally. In the end tens of thousands of indigenous warriors would march with Cortés. He also gained an interpreter, an enslaved woman the Spanish called Doña Marina (Malintzin), whose skill made negotiation — and manipulation — possible.

Cortés entered Tenochtitlan in November 1519 and was received by the emperor Moctezuma, then seized him as a hostage. For months the Spanish held the city in an uneasy grip, until the Aztecs rose against them. On the night of 30 June 1520 — remembered as La Noche Triste, "the Night of Sorrows" — the Spanish were driven out, losing perhaps half their men. It looked like the end of the conquest. It was not.

While Cortés regrouped, an invisible ally went to work. Smallpox, brought unknowingly by the Spanish, broke out in Tenochtitlan and tore through a population with no immunity. It killed vast numbers, including the new emperor, Cuitláhuac, and shattered the city's ability to fight. In 1521 Cortés returned with his indigenous allies and besieged Tenochtitlan for some ninety days, cutting off food and water. On 13 August 1521 the city fell, and with it the Aztec empire.

News of Mexico's gold sent others looking for empires of their own. Francisco Pizarro, an older and harder man who had heard rumours of a rich kingdom in the south, sailed down the Pacific coast. By the time he marched inland in 1532 with fewer than 200 men, smallpox had already raced ahead of any Spaniard, killing the Inca emperor and many of his family. The empire had then torn itself apart in a civil war between two rival brothers, Atahualpa and Huáscar. Atahualpa had just won — and walked, victorious and unsuspecting, straight into Pizarro's path.

At Cajamarca in November 1532, Atahualpa came to meet the strangers almost unarmed, with thousands of attendants but no expectation of a fight. Pizarro sprang an ambush. Spanish guns, steel and cavalry caused panic and slaughter in the square, and Atahualpa was taken prisoner. To win his freedom, the emperor offered a staggering ransom: a room filled once with gold and twice with silver. The Spanish accepted, melted the treasure down — and then, having taken it all, accused him of crimes and executed him in 1533.

With the emperor dead and the empire leaderless, Pizarro marched on Cusco and took it later that year. Resistance went on for decades in the mountains, but the heart of the Inca empire had been seized by a few hundred men. Pizarro's own end came in his own coin: in 1541 he was assassinated in Lima by fellow Spaniards in a bitter quarrel over the spoils.

For Spain, the rewards were almost beyond counting. Ships carried home gold and silver in quantities that reshaped the European economy and made Spain, for a time, the most powerful nation in the world. A new empire — "New Spain" — spread across Mexico, Central America and much of South America, bringing the Spanish language and the Catholic faith that still mark the region today.

For the peoples of the Americas, the same century was a catastrophe with few equals in human history. The wars were brutal, but the diseases were worse: smallpox, measles, influenza and others swept the continent again and again, against bodies that had never met them. Across the Americas, indigenous populations are estimated to have collapsed by anywhere from a half to as much as ninety per cent in the generations after contact. Whole peoples were plundered, enslaved and forced to labour in mines and fields. Empires that had built lake-cities and mountain roads were broken in a few short years.

It is tempting to tell this as a tale of a few daring men and their swords. The truth is harder and stranger. The conquistadors were ruthless and bold, but they did not win on courage alone. They won because they found enemies of the empires willing to fight beside them, because steel and horses gave them a battlefield edge — and, above all, because an invisible plague went ahead of them, emptying the land before they ever raised a sword.