Answer:
The Portuguese prince and patron of sea expeditions who played a key role in the search for sea routes to Asia was Prince Henry the Navigator (1394-1460). He was a member of the Portuguese royal family and is considered one of the most important figures in the Age of Discovery.
Prince Henry sponsored numerous expeditions along the western coast of Africa, hoping to find a sea route to India and the East. He also founded a navigation school and gathered the best cartographers, shipbuilders, and navigators of his time to advance Portuguese knowledge of navigation, shipbuilding, and cartography.
Prince Henry's patronage of exploration and his efforts to develop new navigation techniques and technologies greatly contributed to the Portuguese exploration of Africa and the discovery of new sea routes to Asia. He is considered a key figure in the development of the Portuguese Empire and the Age of Discovery.