Portuguese prince and governor (1394–1460)
Source (Wikipedia): Prince Henry the Navigator

Dom Henrique of Portugal, Duke of Viseu, better known as Prince Henry the Navigator, was a central figure in the early days of the Portuguese Empire and in the 15th-century European maritime discoveries and maritime expansion. Through his administrative direction, he is regarded as the main initiator of what would be known as the Age of Discovery. Henry was the fourth child of King John I of Portugal, who founded the House of Aviz.