While Prince Henry the Navigator never went on any of the expeditions that he chartered, the explorers sailing under his sponsorship ended up discovering a way to navigate down the Atlantic coast of Africa in preparation for rounding the southern tip and heading east to India. His first goal was to find the source of gold in West Africa and the mythical Christian enclave of Prester John, and while he failed in those ends, the fruits of the voyages paved the way for voyages through and around areas that had previously frightened European sailors.
One problem bedeviling sailors in the early years of exploration was the fact that ships designed before 1400 were too heavy and slow to make exploratory journeys. He led the effort to develop lighter, swifter ships capable of undertaking far longer journeys, and the result was the caravel.
Ultimately, the voyages that Henry sponsored when as far south along the Atlantic coast of Africa as Guinea and the town of Lagos. He also hired cartographers to map the coastline of Mauritania. One of the darker sides of Prince Henry's legacy is that he began to bring slaves back to Portugal under the guise of converting them to Christianity.