A good traditional date assigned as the beginning of the Age of Discovery is 1415. In that year, Portugal, having in the past century and half achieved independence from both the Muslims in Iberia and their Christian rivals Castile, initiated a new phase of exploration by conquering the Muslim trading post of Ceuta in northern Africa.
One thing that strikes me about this episode in the history of Western relations with the Middle East is that during the subsequent phase of Portuguese activity, the Muslims were treated as an adversary to be defeated and then circumnavigated. In other words, Prince Henry did not advocate attacking the outposts of Muslim pirates near the Strait of Gibraltar and then settling among them to foster common values. He advocated destruction of any threats to Portugal, but then independence. After exhausting every strategic value he could from Ceuta, his focus shifted to avoiding further entanglements with these enemies, and pursuing profit to empower his native country.
Under his leadership an institute of geography and exploration was founded at Sagres, on the southern tip of Portugal, and wave after wave of Portuguese ships of increasingly advanced design, sought a passage around Africa in order to establish trade with the empires of the East.
The torturous progress of his explorers did not yield that route while he was still alive. They found their way past Cape Verde by 1445, and to the Guinea coast a decade later, but by the time of his death, the Equator had yet to be crossed.
Tragically, Portugal’s kings were not as wise as Prince Henry. His father gradually turned away from the country’s true interest and became entangled in a crusade against the Muslims in northern Africa. Then Portugal’s next king Afonso V, who you might say “stayed the course,” abandoned further exploration in the name of religious warfare. He earned the nickname “the African” for all his efforts, but those same efforts bankrupted his country.
Only after Afonso V died did his successor Joao II re-initiate exploration efforts. Under his leadership the Portuguese rounded the Cape of Good Hood in 1487/88 (more famous than the true southern tip of Africa, Cape Agulhas), and reached Asia in 1498, to subsequently enormous advantages. The tiny nation would create an empire spanning from Brazil to the Indies.