The Age of Exploration

In the fifteenth century the most valuable goods in Europe, spices, silk and porcelain, came from Asia through long chains of middlemen. Each handover added cost. Reaching Asia directly by sea promised enormous profits, and competition among European monarchies gave rulers a reason to fund risky voyages.

Religion mattered too. Portuguese and Spanish rulers saw expansion as a continuation of wars against Muslim states, and they hoped to find Christian allies and new converts. Explorers often wrote about God, glory and gold in the same breath.

• The caravel, a light Portuguese ship with lateen sails that could sail closer to the wind.
• Better use of the magnetic compass, which had reached Europe from China.
• The astrolabe and quadrant for measuring latitude from the height of the sun or Pole Star.
• Accumulated knowledge of Atlantic wind systems, which let sailors loop out to sea and ride the winds home.
• Portolan charts that recorded coastlines and harbours in increasing detail.

Portugal led the way. Sponsored by Prince Henry, often called the Navigator, Portuguese ships worked their way down the West African coast through the fifteenth century, trading for gold and, increasingly, enslaved people. In 1488 Bartolomeu Dias rounded the southern tip of Africa.

In 1498 Vasco da Gama reached Calicut in India. Within a few decades Portugal had built a chain of fortified trading posts from East Africa to the Persian Gulf, India, Malacca and Macau, using naval power to control key points of the Indian Ocean trade.

Christopher Columbus, a Genoese navigator sailing for Spain, believed Asia lay a short distance west across the Atlantic. He underestimated the size of the Earth. In 1492 he reached the Bahamas and then Cuba and Hispaniola, and he insisted to the end of his life that he had reached Asia.

Other voyages soon showed that two vast continents lay in the way. In 1519 Ferdinand Magellan set out to sail around them. He was killed in the Philippines, but one of his ships returned to Spain in 1522, completing the first circumnavigation of the globe.

The historian Alfred Crosby coined the term Columbian Exchange for the transfer of plants, animals, people and diseases between the Old World and the New. Maize, potatoes, tomatoes, cacao and chilli peppers spread from the Americas; wheat, sugarcane, horses, cattle and pigs went the other way.

The potato and maize supported population growth in Europe, Africa and China. But the exchange also carried smallpox, measles and influenza to peoples in the Americas who had no prior exposure. Epidemics, together with war and forced labour, caused a catastrophic population collapse, with many regions losing most of their inhabitants within a century.

Spain conquered the Aztec Empire by 1521 and the Inca Empire in the 1530s, with the help of Indigenous allies and the devastation caused by disease. Silver from mines such as Potosí flowed to Europe and on to China, linking the world economy.

Plantation colonies growing sugar and later tobacco and cotton demanded labour. European traders forcibly transported more than 12 million enslaved Africans across the Atlantic between the sixteenth and nineteenth centuries. The Age of Exploration therefore marks both the beginning of a connected global world and the start of colonial systems whose effects are still felt.