Answer:
Prince Henry "The Navigator" of Portugal was hoping to find a reliable and safe maritime passage to the Far East (India and China).
Explanation:
In 1453, the Ottoman Empire conquered the city of Constantinople, the last remnant of the Eastern Roman Empire (the name "Byzantine Empire" is a misnomer) and trade hub that linked Asian and European merchants. As the Ottomans took over Constantinople, they forbade European merchants from setting foot in the city. As a consequence, the profitable trade of spices (produced mostly in India) went into crisis as it became much more expensive for the Genoans and Venetians to acquire spices from the Arabs.
This whole situation gave the Portuguese the opportunity to explore routes around the coastline of Africa hoping to find a passage into the Indian Ocean and India. It took them half a century to trace this sought-after route which would enable them to make higher profits than the Italians merchants as they did away with the Arab middlemen. So important was this route that the maps of the African coastline and the route itself were declared as the highest secrets of state of the Portuguese kingdom, and anyone found guilty of unduly looking up or sharing this information would be put to death. Also, Portugal had the Pope declare that the use of this maritime route was an exclusive privilege of the Kingdom of Portugal. And as this route was denied to the Spanish, this prompted Columbus to explore a route to Asia sailing westward...
