The city of Lisbon lies at the mouth of the Tagus River, on the Iberian Peninsula at the western end of Europe facing the Atlantic Ocean. In the year 1497, four ships with 168 men left Lisbon, under the leadership of Vasco da Gama, to search for a sea route to India. Twenty-six months later, two ships with forty-four surviving sailors returned to Lisbon with samples of pepper, nutmeg, cinnamon, and cloves. Da Gama had reached India and returned to Europe. For better or for worse, the journey changed the course of history.

For over a hundred thousand years the human race had spread over the whole world, and civilization waxed and waned in the five continents with the different branches of humanity, separated by distance, having little direct impact on each other. The explorers of the Iberian Peninsula conquered the oceans and linked the different branches of humanity. With the discovery of a sea route to India, Europeans would influence events in India and ultimately rule the country. Portugal celebrated the 500th anniversary of this historical event by building Europe's longest bridge at the port from which the ships set sail and named this colossal structure after its national hero – Vasco da Gama.

In the eighth century, the Iberian Peninsula was overrun by the Muslims but over five hundred years from the eleventh to the fifteenth century, the Christians of Europe drove them out of Spain and Portugal. Portugal, which was at the margins of Christian Europe that bordered lands still ruled by Muslims, was infused with a crusading spirit of fighting them for God and for gain.

In the fifteenth century, Venice's maritime strength had converted the Mediterranean Sea into a Venetian pond over which she had an almost total monopoly of the trade with the Muslim ports of the Levant. Spices and silk from the east were exchanged for European gold and silver. Venice grew rich and excited the envy of the rest of Europe. Europe, bleeding gold to the east, replenished its supplies through trade with North African Muslims who brought the precious metal from Africa across the Sahara Desert to the European markets. Ninety per cent of Europe's gold supply in the fifteenth century came from Sub-Saharan Africa.