The Call of the Sea: Why Explorers Risked Everything

In the autumn of 1492, a Italian navigator named Christopher Columbus stood on the deck of a small ship called the Pinta, straining his eyes toward the darkness ahead. He had been at sea for more than five weeks, longer than any of his men had ever sailed from sight of land, and the tension aboard had become almost unbearable. The sailors had begun to whisper about mutiny. Some had already started making dark calculations about throwing their captain overboard if they didn't see land soon. Columbus himself had been forced to maintain two sets of navigation logs—one showing a reasonable distance traveled, and a secret one accounting for the true and far greater mileage—so that his crew wouldn't realize how far they had drifted into unknown waters. Behind them lay everything they knew: Europe, Africa, the familiar coasts of the Mediterranean, the known world. Ahead lay nothing but rumors, legends, and the vast and terrifying expanse of an ocean that no European had ever crossed and survived to describe.

What kind of madness drove men like Columbus to embark on such journeys? What could possibly compel human beings to abandon the safety of solid ground, the comfort of familiar shores, the company of family and friends, to venture into waters that everyone knew were populated by sea monsters,吃不下的 giant waves, and demons waiting to drag the foolish to their deaths? The answer, as we'll discover in this book, is one of the most powerful forces in human history—the irresistible call of the unknown, combined with some very practical pressures that made the late fifteenth century the perfect moment for a maritime revolution that would reshape the entire world.

To understand why explorers were willing to risk everything, we first need to understand what they thought they knew about the world in 1400—and how very little that actually was. The maps that existed at the dawn of the Age of Exploration were remarkable documents of both knowledge and profound ignorance. They showed Europe in considerable detail, the Mediterranean as a well-traveled highway, and the coast of Africa down to about the latitude of modern-day Morocco. Beyond these familiar waters, the maps became increasingly speculative, filled with sea serpents, monstrous creatures, and regions labeled with phrases like "hic sunt dracones"—here be dragons. The great continents of the Americas, Australia, and Antarctica had no place on these maps because no European had ever seen them. The existence of the Pacific Ocean was entirely unknown; when Columbus sailed west in 1492, he was utterly convinced that Asia lay just a few thousand miles across the Atlantic, not realizing that two vast continents and an ocean larger than any European could imagine separated him from his intended destination.

This limited geographic knowledge had profound consequences for trade, diplomacy, and the flow of ideas around the medieval world. For centuries before 1400, the primary conduit for commerce between Europe and the riches of the East had been the legendary Silk Road—a network of overland trade routes stretching from China to the Mediterranean. Spices, silk, precious metals, gemstones, exotic textiles, and countless other luxury goods flowed westward along these routes, creating fortunes for merchants in Venice, Genoa, and other Mediterranean cities. The Republic of Venice, in particular, had built its entire economy on its position as the primary distribution point for Eastern goods entering Europe. Venetian merchants rarely traveled the full length of the Silk Road themselves; instead, they purchased goods from intermediaries at trading posts in the eastern Mediterranean, then resold them at enormous profits throughout Europe.

This system, such as it was, had one critical weakness: it depended on stability. For the overland routes to function, vast stretches of territory stretching from China to the Black Sea needed to be under the control of relatively reliable governments that could protect merchants and their goods from bandits, toll collectors, and hostile neighbors. For most of the thirteenth and fourteenth centuries, such stability existed in the form of the Pax Mongolica—the Mongol Peace—a remarkable period of Mongol rule across most of Asia that had created the largest contiguous land empire in human history. Under the Mongols, trade routes that had been dangerous and unreliable for centuries suddenly became relatively safe. Merchants could travel from one end of the known world to the other with a single passport issued by the Great Khan, passing through a dozen different cultural and political territories without facing the chaos that normally plagued such journeys.

The Mongol Empire at its height stretched from Poland to Korea, from Siberia to Vietnam, encompassing the greatest continuous land empire in history. The Mongols were ferocious conquerors who butchered millions, but they were also sophisticated administrators who understood the value of commerce. Kublai Khan, the Mongol ruler of China during the late thirteenth century, actively encouraged trade with Europe, seeing it as a source of wealth and luxury goods. The famous Venetian merchant Marco Polo traveled to China during this period, spending more than two decades in the service of Kublai Khan, and his fantastical account of his travels—describing the wealth of Cathay in terms that seemed to border on the impossible—captured the European imagination for generations. The Polos may or may not have actually traveled as far as China; some scholars believe Marco Polo's account was based more on Persian merchant sources than personal experience. But whether his stories were entirely true or partly invention, they painted a picture of unimaginable riches waiting in the East—cities paved with gold, palaces with walls of silver, a civilization so advanced that it made Europe look like a collection of backward villages.

This was the world that European merchants knew in the early fourteenth century: a world of dangerous but possible overland trade, of Venetian fortunes built on spices and silk, of Marco Polo's legends sparking dreams of Eastern wealth. It was not an ideal system—the journey from Europe to China and back could take years, and the costs of transporting goods over thousands of miles of difficult terrain were enormous—but it worked. Merchants could count on steady profits, and the flow of Eastern luxuries into Europe continued, if not in vast quantities, then at least reliably.

Then, in the middle of the fourteenth century, everything collapsed.

The first blow came in the form of the Black Death, the most devastating pandemic in human history. The plague, caused by the bacterium Yersinia pestis and likely spread along the same trade routes that had made the Pax Mongolica possible, swept across Asia and Europe between 1346 and 1353, killing an estimated 75 to 200 million people—somewhere between 30 and 60 percent of Europe's population. The social and economic disruption was catastrophic. Entire villages were abandoned. Crops rotted in the fields for lack of workers to harvest them. The feudal system that had structured European society for centuries began to break down as labor became scarce and survivors found themselves with unprecedented leverage to demand better conditions. The disruption to trade was equally severe. Merchants died or fled. Caravanserais along the Silk Road stood empty. The careful web of commercial relationships that had sustained the overland trade system frayed and unraveled.

But the Black Death was only the beginning of the troubles that befell the Eurasian trade routes. As the Mongol Empire expanded, it had always been difficult to hold together—a realm stretching from one end of the known world to the other was inherently unstable, dependent on the personal authority of a succession of capable rulers. When those rulers proved less capable, or when succession disputes erupted, the empire fractured. By th