The Cortes of Coimbra, the battle of Aljubarrota and the treaty of Windsor mark the three final stages in the consolidation of the monarchy. A period of expansion oversea began in the same reign, with the capture of Ceuta in Morocco. The three eldest sons of King John and Queen Philippa, Edward, Peter and Henry (afterwards celebrated as Henry the Navigator) desired to win knighthood by service against the Moors, the historic enemies of their country and creed. In 1415 a Portuguese fleet, commanded by the king and the three princes, set sail for Ceuta. The town was captured and garrisoned, and thus the first Portuguese outpost was established on the mainland of Africa.