Age of Discovery and Exploration
THE AGE OF DISCOVERY AND EXPLORATION
After this assignment, you should be able to define and discuss the following
- Prince Henry "The Navigator", Christopher Columbus, Eratosthenes, Marco
Polo, Queen Isabel of Castile, Vasco da Gama, Amerigo Vespucci, Ferdinand
You should also have been considering the following matters:
- Why did the Portuguese undertake sea-exploration?
- How could the medieval Europeans have been so sure that the Earth was a
- How did Eratosthenes determine the distance around the Earth?
- Why did Columbus believe the traditional ideas about the distance around
the Earth were wrong?
You might also think about some matters that we have not addressed directly:
- If so many people already knew of the existence of land to the west, what
made Columbus' voyage of discovery significant?
- What caused this burst of activity that we call The Age of Discovery
- Were there other "voyages of discovery and exploration" going on within
The diet of the Europeans in the middle ages was pretty bland. At least they
thought so, and they were willing to pay a high price for aromatic spices
brought in from the East. Cloves, tamarind, mace, cinnamon, allspice, nutmeg,
saffron, white and black pepper, anise, and even sugar coming from India and
Indonesia provided the trading goods that led to a great network of trading
routes that spread throughout the Eurasian and African continent. Europe was at
the Western end of this network, and, after passing through so many hands, the
spices that arrived there were quite costly. The merchant-states of Italy --
Genoa, Pisa, Venice, Naples, Palermo -- had established trading posts in the
eastern Mediterranean and along the coast of the Black Sea, and it was they who
carried the spices on the last leg of their journey to Europe and it was they
who sold those spices at a high price and for a great profit.
Many of the other European states envied the Italian city-states, especially
because purchasing spices drained their economies of gold and silver. In the
mid- fifteenth century, the Portuguese government decided to try to bypass the
Italians and other middle men, and to find an all-water route to the source of
those spices. Under the direction of Prince Henry "The Navigator" (1394-1460),
well-planned expeditions were sent southward annually from 1418 to explore the
African coast and to establish forts and trading posts along its extent. By
1444, they had reached Cape Verde and had built up a thriving trade in gold,
ivory, and other goods. In 1487, Bartolomeo Dias rounded the Cape of Good Hope,
and it became clear that the sea-lanes to India were clear.
Spain was not happy at the prospect of its small neighbor gaining control of
a trade that would make it the richest kingdom in Europe, but there was little
the Spanish rulers could do about it. They were getting ready to mount a
campaign to drive the Muslims from the last bit of territory they had taken from
the Christians almost eight hundred years before, and they had very little money
to invest in anything else. This is where Christopher Columbus
comes in. There are a lot of misconceptions about Columbus that it would be well
to clear up. The most common misconception is that Columbus believed that the
world was round and that everyone else thought it was flat.
As a matter of fact, everyone knew that the Earth was a sphere.
Kings were normally portrayed, on coins and elsewhere, holding stick and a ball.
The stick is the scepter, and the ball is the orbis terrarum, the symbol
of "sphere of the earth." The little cross at the top marks the location of
Jerusalem and the T- shaped bands represent the division of the continents of
Africa, Asia, and Europe.
What's more, most educated Europeans had a pretty good idea of how large the
earth was. That had been rather ingeniously determined in about 240 BC by
Eratosthenes, a scholar at the Library and Museum in Alexandria.
Some distance south of Alexandria, there was a very deep and very straight
well, so deep, in fact, that sunlight reached its bottom only at noon on one day
of the year. Eratosthenes saw that the well must be pointing directly toward the
center of the Earth and so the sun was exactly above that well only at that one
time during the year. He figured that the sun was so far away that its rays were
just about parallel when they reached the Earth, and that noon would come at the
same time as at the well at any spot directly north or south. So he set up a
tall and straight pole some distance north of the well, balanced so that it,
too, pointed toward the center of the Earth. He then waited until noon and then
measured the length of the shadow cast by the pole.
Things were pretty straightforward after that. He knew the height
of the pole and the length of the shadow, so he had two sides of a triangle, and
the pole was perpendicular to the Earth's surface, so he had a ninety degree
interior angle. That made it easy to calculate angle A, formed by the pole and
the sun's rays. Knowing that, when a straight line crosses two parallel lines,
the opposite angles formed are equal, he then knew what the angle was between
his pole, the center of the earth, and the deep well. Since he knew the distance
between his pole and the deep well, he knew that distance had the same
relationship to the distance around the Earth as angle A had to the
circumference of a circle. Quod erat demonstrandum.
A century before, A Venetian merchant by the name of Marco Polo
had travelled to China and back, and had left a detailed account of his
journeys, so people had a pretty good idea of how far it was from Europe to
China and India. It was not hard to subtract that distance from the
circumference of the Earth and realize that you would have to sail West a
long way to get to India.
So where does Columbus come in? Columbus was an experienced navigator from
the Italian city of Genoa who had been studying geography and old travel
accounts, including that of Marco Polo, for some time. He had come up with the
strange idea that the Earth was not round, but shaped like an egg, that the
ancient geographers had measured it the long way around (from north to south),
and that its circumference was much less when measured from east to west. His
figures showed that it was a relatively easy sail from the Canary Islands (where
there was always a favorable wind blowing west) to India.
There were a number of very good reasons for considering his theories about
the shape of the Earth to be more than a bit crackpot, but most people who were
interested in such things knew that there was some big land mass not all that
far to the west. The Vikings had explored some of the coast of North America in
1000, and had established colonies in Greenland, Newfoundland, and islands in
the estuary of the St. Lawrence River, colonies that endured for a long time.
What is more, the Vikings had composed accounts of these explorations and
settlements, accounts that were relatively well-known, at least in northern
Europe and Iceland. Besides, the sea around the St. Lawrence estuary (the
Grand Banks was teeming with marine life, and Portuguese cod-fishers and
Basque whalers had been hunting those waters (and setting up processing stations
on shore) for many years. The Europeans knew of this land-mass, but most were
certain that it was neither China nor India.
Nevertheless, Queen Isabel of Castile was willing to take a
gamble, even if it was a long-shot, to try to beat the Portuguese to the riches
of the Orient. She gave Columbus three old and leaky ships -- the smallest no
bigger than a modern life-boat -- and emptied a small-town jail to provide him
with a crew. He proceeded south to the Canary islands, refitted his little
ships, took on supplies, and then caught the westerly winds on 6 September 1492.
He landed on one of the islands of the Bahamas on 12 October, a voyage of a
little over five weeks. After some exploration and leaving a small fort and
garrison behind, he returned to Spain. He landed on 15 March 1493 and announced
that he had reached India. Not too many people believed him, but it was enough
for Spain to ask the pope for an injunction against the Portuguese continuing to
sail east into what the Spanish claimed was now their territory.
This diplomatic wrangling did not last long, however, and, in 1497, a small
Portuguese fleet under the command of Vasco da Gama made a round
trip from Lisbon to Calcutta and return. In the same year, John Cabot, of
England, explored the coast of North America. In 1501, a Portuguese expedition
commanded by Amerigo Vespucci, from the Italian city of Florence,
explored the South American coast. Vespucci later published his conclusion that
this western land-mass was a great continent, and geographers soon began calling
this continent America. Finally, in 1519-1522, a Spanish fleet under the
command Ferdinand Magellan managed to sail completely around the
In the years that followed, European fleets -- first those of the Spanish and
Portuguese, and then those of the French, English, and Dutch -- gained control
of the world's sea-lanes. Where the local population was dense, they established
fortified settlements on islands of the coast, but where the local residents
could not effectively defend themselves, they moved inland along the rivers to
establish colonies to exploit the rich resources of what was essential virgin
There is a text
outline of the age of discovery and exploration that will provide you with
an overview of the period and movement. The Discoverers Web
Homepage offers a number of links to full discussions of several things upon
which we have only touched. Finally, the Library of Congress has mounted a major
exhibit, called 1492, that will
be well worth your while to see.
If you have the time, you might want to get an early start in visiting Expo98, this year's world's
trade fair, being held in Lisbon, Portugal, and dedicated to The World's Oceans.
The site is still under construction, but is fun to explore. Be sure to see The
Portuguese Pavilion, which will feature the Portuguese contribution to opening
the world's seaways. You can find out a great deal about the knowledge of
geography in the time of Columbus by visiting the exhibit Expanding
This text was produced by
Lynn H. Nelson,
University of Kansas.
12 January 1998