THE GREAT VOYAGES 53
Prester John, who was already identifi ed with the
emperor of Abyssinia, although no one knew how
far his empire extended. An alliance with this ruler,
it was hoped, would encircle the Muslims in North
Africa with a powerful league of Christian states.
Efforts to expand the Moroccan beachhead,
however, made little progress. If the Portuguese
could not penetrate the Muslim barrier that sepa-
rated them from the southern sources of gold and
the kingdom of Prester John, could they not reach
these goals by sea? In 1419 Henry set up a head-
quarters at Sagres on Cape St. Vincent, the rocky
tip of southwest Portugal. Here he assembled a
group of expert seamen and scientists. At the nearby
port of Lagos, he began the construction of stronger
and larger ships, equipped with the compass and
the improved astrolabe. Beginning in 1420, he
dispatched several ships to explore the western
coast of Africa. Each captain was required to en-
ter in his log data concerning currents, winds, and
calms and to sketch the coastline. An eminent con-
verso mapmaker, Jehuda Crespes, used these data
to produce more detailed and accurate charts.
The fi rst decade of exploration resulted in the
discovery of the Madeiras and the Azores. But
progress southward was slow; the imaginary bar-
riers of a fl aming torrid zone and a green sea of
darkness made sailors excessively cautious. Pas-
sage in 1434 around Cape Bojador, the fi rst major
landmark on the West African coast, proved these
fears groundless. Before Henry’s death in 1460,
the Portuguese had pushed as far as the Gulf of
Guinea and had begun a lucrative trade in gold
dust and slaves captured in raids or bought from
coastal chiefs. Henry’s death slowed the progress
of exploration, but the advance down the African
coast continued, under private auspices and as an
adjunct to the slave trade, the fi rst bitter fruit of
European overseas expansion. In 1469 a wealthy
merchant, Fernão Gomes, secured a monopoly of
the trade to Guinea (the name then given to the
whole African coast), on the condition that he ex-
plore farther south at the rate of one hundred miles
a year. Complying with his pledge, Gomes sent his
ships eastward along the Gold, Ivory, and Slave
coasts and then southward almost to the mouth of
the Congo.
THE SEA ROUTE TO THE EASTUnder the energetic John II, who came to the
throne in 1481, the crown resumed control and
direction of the African enterprise. At Mina, on
the Gold Coast, John established a fort that became
a center of trade in slaves, ivory, gold dust, and a
coarse black pepper, as well as a base for further ex-
ploration. Henry had dreamed of fi nding gold and
Prester John, but King John was more concerned
with the project of reaching India by rounding Af-
rica. In 1483 an expedition commanded by Diogo
Cão discovered the mouth of the Congo River and
sailed partway up the mighty stream. On a sec-
ond voyage in 1484, Cão pushed as far south as
Cape Cross in southwest Africa. The Portuguese
monarch sensed that victory was near. In 1487 a
fl eet headed by Bartholomeu Dias left Lisbon with
orders to pass the farthest point reached by Cão
and if possible sail around the tip of Africa. After he
had cruised farther south than any captain before
him, a providential gale blew Dias’s ships in a wide
sweep around the Cape of Good Hope and to land-
fall on the coast of East Africa. He had solved the
problem of a sea road to the Indies and returned to
Lisbon to report his success to King John.
The route to the East lay open, but domestic and
foreign problems distracted John’s attention from the
Indian enterprise. He died in 1495 without having
sent the expedition for which he had made elaborate
preparations, but his successor, Manuel I, known as
the Fortunate, carried out John’s plan. In 1497 a fl eet
of four ships, commanded by the tough, surly noble-
man Vasco da Gama, sailed from Lisbon on a voyage
that inaugurated the age of European colonialism in
Asia. After rounding the Cape, da Gama sailed into
the Indian Ocean and up the coast of East Africa. At
Malinda, in modern Kenya, he hired an Arab pilot,
who guided the fl eet to Calicut, the great spice trade
center on the west coast of India. Received with hos-
tility by the dominant Arab traders and with indiffer-
ence by the local Indian potentate, who scorned his
petty gifts, the persistent da Gama managed to load
his holds with a cargo of pepper and cinnamon and
returned to Lisbon in 1499 with two of the four ships
with which he had begun his voyage. A new fl eet,
commanded by Pedro Álvares Cabral, was quickly