Henry the Navigator, son of John I., king of Portugal, born at Oporto; an able, enterprising man, animated with a zeal for maritime discovery, and who at his own expense sent out voyagers who discovered the Madeira Islands and explored the coast of Africa as far as Cape Blanco; is said to have been the first to employ the compass for purposes of navigation; his mother was daughter of John of Gaunt (1391‒1460).
Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)
Henry of Huntingdon * Henry, Matthew