Billie Silvey
September 2013
Portugal faces the Atlantic, not the Mediterranean.  Its
sailors, led by their prince,
Henry the Navigator, had the
risky idea that sailing around
Africa would lead them to
India with its rich trade.  That idea was unconfirmed by
maps of the time, which were based on
Ptolemy.  At the
time, a certain point along the west coast of Africa was  
the end of the known world.  

Daniel J. Boorstin points out in his best seller, The
Discoverers:  A History of Man's Search To Know
His World and Himself,
"In the Crusaders' world the
known was dogma and the unknown was unknowable.  
But in the explorers' world the unknown was simply the

Separated from Africa by the Straits of Gibraltar,
Portugal was more pluralistic, less provincial than the
other nations of Europe.  Its people had intermarried
with Africans and Asians.  They were a mixture of
religions—Christians, Jews and Muslims.

In a crusade against a Muslim trading center opposite
Gibraltar, Henry had encountered caravans bringing
wheat, rice, salt and spices from India, leading him to
postulate a route to India from Africa.  He recognized
the importance of feedback—not just reaching a new
place, but returning home and sharing what had been

Henry left his court at Lisbon for
Sagres, at the tip of the
promontory extending from the southwest corner of the
country, where he founded a center for cartography,
navigation and shipbuilding.  From there, he sent out
explorers for the next 40 years.  He brought
Cresques, a Catalan Jew from Majorca, to Sagres to
compile the reports brought back by his explorers.

Henry made cartography cumulative by having
geographical details marked on navagational charts,
beginning with his brother Pedro's copy of
Marco Polo's
map and travel records.

He tested navigational instruments and developed the
caravel, a large, new ship designed to sail into the wind,
so sailors could return from their explorations.  It was
more maneuverable than earlier ships, with a shallower
draft and slanting and triangular sails.

Henry devised an organized (step-by-step) approach to
discovery.  He was in it for the long haul, which was a
good thing, because it took a century and a half for the
Portuguese to complete their discoveries.  

Henry was collaborative, depending on heroic people,
not a single hero.  His method formed the prototype for
modern exploration and discovery.

Bartholomeu Diaz took two caravels and a store
ship down the coast of Africa where they were driven
south by a storm into cooler waters than Europeans had
traveled before.  Steering east and north, they finally
anchored in Mossel Bay near Cape Town.  The storm
had driven them around the tip of Africa.

Diaz wanted to go on to India, but his crew voted to go
back with the news that you could sail around the tip of

Christopher Columbus was in Lisbon when Diaz
returned.  He saw this discovery as a loss for himself and
his plan to sail the opposite way to reach India.

Columbus's claim to islands in the Atlantic led to a
dispute between Portugal and Spain.  They appealed to
Pope, who established a line running north and south
1,200 nautical miles west of the Cape Verde Islands,
with lands west of the line going to Spain and those east,
to Portugal.  

That line gave Brazil to Portugal, making Brazil the only
non-Spanish-speaking country in South America to this

In 1497, King Manuel I sent
Vasco da Gama to
complete the voyage.  He took four ships, two square-
rigged, a caravel and a store ship with provisions for
three years, maps and instruments.  

Upon reaching Malindi, in Kenya, Da Gama was guided
by the great Arab master of navigation,
Ibn Majid across
the Indian Ocean to Calcutta.  Da Gama reached India
and began trade, establishing Portugal in place of Venice
as the trade center of Europe.  In helping Da Gama find
a route from Africa to India, Ibn Majid inadvertently
helped end the domination of Arabic navigation in the
Indian Ocean.
A Portuguese caravel
An early compass.
A map of Europe, Asia and Africa
showing Portugal (in red) and the extent
of European knowledge of Africa (tan line
down coast to equator) before Henry the
Navigator's sailors pressed on around the
Cape of Good Hope to the Middle East
and India.
Prince Henry the Navigator (in black)
with his sailors accumulating knowledge
of geography and navigation, ship and
instrument building.
Cape of Good Hope
Above: Statue in Lisbon of
Portuguese explorers, with
Prince Henry at right holding a

Right: A compass rose mosaic
in Belen.