In the 14th and 15th centuries, Porto's shipyards contributed to the development of Portuguese shipbuilding. Also from the port of Porto, in 1415, Prince Henry the Navigator (son of John I of Portugal) embarked on the conquest of the Moorish port of Ceuta, in northern Morocco. This expedition by the king and his fleet, which included Prince Henry, was followed by navigation and exploration along the western coast of Africa, initiating the Portuguese Age of Discovery. The nickname given to the people of Porto began in those days; Portuenses are to this day, colloquially, referred to as "tripeiros" (), referring to this period of history, when higher-quality cuts of meat were shipped from Porto with their sailors, while off-cuts and by-products, such as tripe, were left behind for the citizens of Porto; tripe remains a culturally important dish in modern-day Porto.