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Europeans Begin Overseas Exploration

Europeans had been trading in exotic and often dangerous places for centuries, but European overseas exploration began in the early fifteenth century. The fact that Muslims were making travel and trade by land difficult for Europeans did not make Europeans launch immediately into the Atlantic Ocean in search of a new world, though. Europe had to ease into this new form of exploration.

European sailors of the fifteenth century did not believe the world was flat, so that wasn’t what kept Europeans close to the shore. Rather, the technology that eventually would make ocean voyages possible simply wasn’t available prior to the fifteenth century. Ships weren’t built and equipped for ocean voyages, maps weren’t extensive enough, and a body of knowledge of open-sea travel simply did not exist. Thanks to Portugal, though, that was about to change.

Would You Believe?

Although there is some debate about the authenticity of the stories, Prince Henry “the Navigator" is said to have founded Europe's first navigational school where students learned skills such as navigation and cartography.

Portugal sat virtually isolated on the outer edge of the Iberian Peninsula, so it was only natural that Portuguese traders and explorers took to the seas. Early in the fifteenth century, Portugal conquered the Muslim town of Ceuta in Morocco. On that expedition was the young son of Portugal’s King John I (1357-1433). Prince Henry (1394-1460), also known as Henry the Navigator, later led the Portuguese southward from Portugal to the Canary Islands and to the Azores. Henry also sponsored expeditions southward along the African coast where the Portuguese established a lucrative gold and slave trade. With each journey, the Portuguese explored a little more, learned a little more, tweaked their maps, and gained valuable information for use on the next journey.

Cutting-Edge Technology

In the decades prior to the launch of overseas expeditions, Europeans made improvements in a number of areas and fine-tuned some instruments and equipment that allowed their expeditions to become increasingly successful. Although some famous explorers claimed that maps were practically useless to them, maps played a large role in the boom in overseas exploration.

Before the fourteenth century, most “world maps” relied on classical maps and descriptions of the world along with information from travelers, which proved to be shaky, at best. Most maps included only the Mediterranean region and many had the city of Jerusalem at the center. Few people had any idea how inaccurate these maps really were.

In 1375, Abraham Cresques created the Catalan World Atlas, a much more useful map of the Mediterranean than anything before it, complete with sailing instructions and compass readings. From here, maps continued to improve, with every expedition adding to the body of knowledge. Cartographers also added grids to some of the newer maps in this era, grids that eventually would become latitude and longitude lines.

Maps certainly weren’t the only things that received upgrades during the age of exploration. Ships, too, received overhauls. The medieval galleys of Europe did well along the European coast, but they weren’t built for seafaring. Hull construction changed at some point during the age of exploration, allowing for more storage and more stability.

Would You Believe?

Historians have very few details about how ships were constructed during this time. Most of the information about these ships has been reconstructed based on models, journal entries, and a very few preserved examples of the ships.

Another change was sails. Most ships of the day were equipped with both sails and oars because ships couldn’t always count on the winds and the currents to be favorable. The caravel helped fix this problem. The caravel was a ship with large square sails for moving forward and small triangular sails for sailing diagonally into a headwind. The caravel made it possible to sail into the wind. The caravel didn’t sail straight into the wind; simple physics prevents that. However, the triangular sails allowed the caravel to travel across the wind in a zig-zag pattern. Caravels also benefited over the years from stronger sails and ropes, which allowed for smaller crews, better decking, better rudders, and more.

The basic compass had been around for at least a few centuries in Europe and for much longer in China. However, a new and improved compass emerged that had a disk displaying degrees beneath the compass needle. As the maps became more precise, the new compass became more important. Another navigational tool that improved during this time was the astrolabe. The astrolabe measured the distance of the sun and stars above the horizon and allowed for fairly accurate calculations of a ship’s distance above and below the equator. For example, if the North Star measured 25° above the horizon, the sailor knew his ship was 25° above the equator, and so on. This system worked pretty well as long as the ship wasn’t too close to the equator; when the readings became inaccurate, the sailors used the sun instead of the North Star. The astrolabe, like the compass, became more useful as maps became more precise.

Going East by Sailing West

Much of the “information” and “knowledge” of the world and the oceans during the Middle Ages was based on the science and philosophy, or speculation, of Greek scholars. While many classical calculations were remarkably accurate, many weren’t. The same holds true for the more modern works like Pierre d’Ailly’s Image of the World from 1410.

Pierre d’Ailly (1350-1420) believed that oceans covered only about one fourth of the earth’s surface and that the Atlantic Ocean was not very wide at all. In his treatises, d’Ailly uses ideas from Ptolemy, Aristotle, and others, including Aristotle’s reasoning that West Africa must be close to East India because elephants existed in both places. This information helped convince people that a new route to Asia, which by land lay geographically east of Europe, could be found by sailing west.

Would You Believe?

Pierre d'Ailly was also a high-ranking Church official and conciliarist who worked to heal the wounds of the Great Schism (see Chapter 1).

The importance of this idea was not that it was possible to do so—after all, everyone knew the earth was round—but that it was reasonable and even practical. If d’Ailly was correct, ships could sail west from Europe and reach Asia in a matter of days, especially if the winds were favorable. By the calculations of Columbus and others, Asia lay only about 5,000 miles to the west.

In reality, the estimate was about 7,000 miles off. But this not-so-sound logic eventually would lead to one of the greatest discoveries (or blunders, depending on your perspective) in all of history.

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