Before 1400: A World of Isolated Worlds

If you could have teleported a 15th-century Guangzhou tea merchant straight to the market square of Tenochtitlan (the Aztec capital, in what’s now Mexico City) in the year 1400, the two men would have stared at each other like one was an alien. The Chinese trader would have gaped at the Aztec’s iridescent quetzal-feather headdresses and cacao beans used as currency; the Aztec merchant would have thought the Chinese man’s silk robes and delicate porcelain cups were magic tricks. That’s how disconnected the world was at the dawn of the 1400s: a patchwork of isolated “world bubbles,” each convinced their small corner of the planet was the entire universe. Most people alive at the time had no idea that entire continents full of people, cities, and entirely different ways of life existed just across oceans they’d never even heard of.

To understand how the global trade network was built, we first have to wrap our heads around just how fragmented the world was before sustained transoceanic contact. This wasn’t because people were uninterested in the wider world—trade routes crisscrossed Europe, Asia, and Africa, and travelers did make long, dangerous journeys between regions. But these connections were narrow, slow, and almost entirely limited to the “Old World” of Eurasia and Africa. The Americas, Australia, and most of the Pacific were completely unknown to people in the Old World, and vice versa. There was no such thing as a “global” economy, no shared pool of knowledge, no exchange of crops or animals between continents. Every civilization was developing on its own, with only limited, one-way trickles of goods and ideas filtering in from neighboring regions.

The Old World’s Fragile Web of Connections

The most connected part of the 1400 world was the vast landmass of Eurasia, plus the northern half of Africa. For thousands of years, traders, pilgrims, and armies had moved along overland and coastal routes, carrying goods, technologies, and religious ideas across thousands of miles. The most famous of these was the Silk Road, a network of routes that linked the Chinese court to the markets of the Mediterranean. But the Silk Road was never a single, direct highway: it was a chain of smaller routes, with goods changing hands dozens of times between the moment silk left a workshop in Chang’an (modern Xi’an) and the moment it ended up in a Roman noble’s villa.

A bolt of Chinese silk might first be sold to a Central Asian Sogdian trader, who carried it west to a market in Samarkand, where it was bought by a Persian merchant, who took it to Baghdad, where an Arab trader purchased it to sell to a Venetian merchant in Constantinople, who finally shipped it to Rome. By the time it reached its final buyer, the silk cost 10 to 20 times what it had originally sold for in China. For most of history, neither the Chinese producer nor the Roman buyer had ever met, or even had an accurate idea of where the other lived. The Chinese called the Roman Empire “Daqin” and knew it as a distant, wealthy state far to the west, but they had no reliable maps of the lands between China and Rome, and no way to travel there directly. The Romans knew silk came from a land called “Seres” (the “Silk People”) but thought it was a mythical place at the edge of the world, where silk grew on trees and was harvested by giant, worm-like creatures.

The Silk Road was never just about silk, of course. Traders carried spices from India and Southeast Asia, precious stones from Central Asia, horses from the steppes of Mongolia, glassware from the Levant, and paper and gunpowder from China. Religious ideas traveled the same routes: Buddhism spread from India to China, Central Asia, and eventually Korea and Japan; Nestorian Christianity made its way to China by the 7th century; and Islam spread rapidly across Central Asia, North Africa, and parts of South Asia after the 7th century. But these connections were fragile, dependent on stable empires to keep trade routes safe from bandits and war. When the Mongol Empire collapsed in the 14th century, the Silk Road became far more dangerous, and trade between East and West dropped sharply.

Coastal trade in the Indian Ocean was far more reliable than the overland Silk Road, and by 1400 it was the most vibrant trade network in the Old World. Arab, Indian, and Chinese merchants used seasonal monsoon winds to sail back and forth between the Swahili Coast of East Africa, the Arabian Peninsula, India, and Southeast Asia. A ship from Guangzhou could sail to Calicut (on India’s west coast) in a few months, riding the summer monsoon winds, then turn around and ride the winter monsoon winds back to China. These merchants traded Chinese porcelain and silk for Indian spices (pepper, cinnamon, cloves) and cotton textiles, African gold and ivory for Arabian dates and Persian carpets.

But even this bustling Indian Ocean network had hard limits. No ship in 1400 could sail directly across the open ocean: all voyages stuck close to coastlines or island chains, stopping at ports along the way to resupply. No Indian Ocean trader had ever sailed around the southern tip of Africa (the Cape of Good Hope) to reach the Atlantic, and no European ship had ever sailed around Africa to reach the Indian Ocean. The farthest west Indian Ocean traders went was the Swahili Coast (modern-day Kenya and Tanzania); the farthest east they went was the Indonesian archipelago. They had no idea the Americas existed, and no idea that the Pacific Ocean was a vast, open sea stretching all the way from Asia to the Americas.

North Africa was connected to the rest of the Old World via the Mediterranean, and via trans-Saharan trade routes that linked the Maghreb (modern-day Morocco, Algeria, Tunisia) to the great empires of West Africa: Ghana, Mali, and Songhai. Camel caravans carried salt from the Sahara south to West Africa, and carried gold, ivory, and enslaved people north to the Mediterranean. The Mali Empire’s ruler Mansa Musa, who made a famous pilgrimage to Mecca in 1324, brought so much gold with him that he crashed the price of gold in Egypt for a decade. But even this trade was limited: most North African merchants never traveled south of the Sahel (the semi-arid region just south of the Sahara), and most West African rulers and traders had only vague, secondhand ideas of the lands north of the desert. They knew there were wealthy states across the sand, but they had no direct contact with Europe, Asia, or the Mediterranean world beyond the North African traders who came to their markets.

Even within the Old World, connections were spotty. Most people in 1400 never traveled more than 50 miles from their birthplace. A peasant in rural France might have heard of “the Indies” as a distant, wealthy land, but had no idea where it was, or what the people there were like. A farmer in rural China might have heard of “the Great West” as a place of barbarians, but had no idea there were vast empires and civilizations across the deserts and mountains to the west. For the vast majority of people, their “world” was their village, their local market, and the nearby towns they might visit once or twice a year. The idea of a connected global community was completely unthinkable.

The Americas: A Whole World Untouched

While Eurasia and Africa had a fragile web of connections, the Americas were completely cut off from the rest of the world. By 1400, the Americas were home to some of the most sophisticated civilizations on the planet: the Aztec Empire in central Mexico, the Maya city-states in the Yucatán Peninsula and Central America, and the Inca Empire stretching along the Andes Mountains from modern-day Colombia to Chile. These civilizations had built massive cities, developed complex writing and mathematical systems, engineered advanced agricultural terraces and aqueducts, and created rich artistic and religious traditions.

But they had no contact with Eurasia or Africa. Not a single pe