Some of the earliest significant voyages of European exploration in the fifteenth and sixteenth centuries were conducted by the Portuguese. From the very start, the Portuguese state was heavily involved in sponsoring and supplying the voyages. Around the year 1418, Prince Henry of Portugal began sending explorers into the Atlantic to chart the African coast on a yearly basis. He also founded navigational and maritime schools in order to prepare Portugal to become the preeminent maritime power of Europe.
Portuguese rulers were very eager for this to happen. Until this time, various Italian states had the largest European hand in the spice trade. The Portuguese were hoping that by discovering new sea routes utilizing their geographic position on the western edge of Europe, they might be able to sidestep the many middlemen usually involved in this lucrative business. Furthermore, rumors of ample supplies of gold in Africa during a time of gold shortages in Europe were enough to send many Portuguese ships to investigate these claims.
Furthermore, there was indeed a religious element to Portuguese exploration. Prince Henry and other Portuguese leaders were eager to learn more about the Muslim populations of Africa. With the Crusades coming to an end in the Near East, there were many Christians who wanted to continue the religious struggle against Muslims elsewhere. They hoped to conquer the Muslim lands of West Africa and spread Christianity throughout the region. Not much ever came of these pursuits, but Catholic missionaries did sail aboard most Portuguese voyages of exploration.