In the 14th and the 15th centuries, the shipyards of Porto contributed to the development of the Portuguese fleet. In 1415 Henry the Navigator, son of João I, left from Porto toconquest the Muslim port of Ceuta in northern Morocco. This expedition led to the exploratory voyages that he later sent down the coast of Africa. Portuenses are referred to this day as “tripeiros”, in reference to the fact that higher quality meat would be loaded onto ships to feed sailors, while off-cuts and by-products such as tripe would be left behind and eaten by the citizens of Porto. Tripe remains a culturally important dish in modern day Porto.

In the year 1415  were built on the banks of the Douro the ships and boats that were to lead the Portuguese, this year, the conquest of Ceuta and, later, to the Discoveries. The reason for this development was secret and shipyards rumors were many and varied: some said that the vessels were intended to convey the Infanta D. Helena to England, where she married, others said it was to bring King D. John I to Jerusalem to visit the Holy Sepulchre. But there were also those who claimed that the feet together armada was intended to drive D. Infants Peter and D. Henry to Naples to marry there …

It was then that Prince Henry appeared unexpectedly in Oporto to see the progress and although pleased with the effort expended, thought it could do even more. Then confided to Infante Master Vaz, faithful in charge of construction, the true and secret reasons that lay behind it: the conquest of Ceuta. Asked the master and his men harder and sacrifice, to what Master Vaz assured him that they would do for the same infant who had made about thirty years ago when the war with Castile: give all the meat in town and would eat only the guts . This sacrifice had been worth it to them the nickname “tripeiros”. Moved, the Prince Henry then told him that this name “tripeiros” was a real honor for the people of Oporto. The History of Portugal recorded another sacrifice of heroic unusual “tripeiros” which contributed to the large fleet of Prince Henrique, with seven galleys and twenty ships, leave the path of conquest of Ceuta.