distinguished themselves and were knighted. As the youngest of many sons, Ferdinand did not obtain a substantial endowment from his father, only the Lordship of Salvaterra de Magos and a lifetime grant of Atouguia in 1429. In 1434, after the death of his father John I and the administrator João Rodrigues de Sequeira, Ferdinand was appointed lay administrator of the Knightly Order of Aviz by his brother King Edward of Portugal. Ferdinand was also offered the titular office of cardinal by Pope Eugene IV, but turned it down. Despite his piety, Ferdinand had no intention of pursuing a clerical career. Siege of Tangier In 1436, dissatisfied with his meager domains, Ferdinand asked his brother King Edward for permission to go abroad to seek his fortune in the service of a foreign king (reportedly, Henry VI of England). Ferdinand's request prompted the reluctant Edward to endorse a plan, long promoted by his brother Henry the Navigator, to launch a new Portuguese campaign of conquest against Marinid Morocco. As a bachelor, Ferdinand made out a will naming Edward's second son, the Infante Ferdinand (future Duke of Viseu) as his heir before departing. In August 1437, the Portuguese expeditionary force, under the leadership of Henry the Navigator, set out to seize Tangier. Ferdinand brought his household and Aviz knights with him, choosing as his personal banner an emblazoned image of the Archangel St. Michael. The Tangier campaign proved to be a disastrous fiasco. Henry impetuously launched a series of assaults on the walls of Tangier with no success, while allowing his siege camp to be encircled by a Moroccan army rushed north by the Wattasid strongman Abu Zakariya Yahya al-Wattasi, governor of the Marinid palace of Fez (called Lazeraque by the Portuguese chroniclers). The Portuguese besiegers, now besieged and unable to break out, were starved into submission. To preserve his army from destruction, Henry the Navigator signed a treaty in October 1437 with the Moroccan commanders. It called for the restoration of Ceuta (which had been captured by the Portuguese back in 1415) in return for allowing to his army to withdraw intact (albeit with their weapons left behind). By the terms of the treaty, Henry handed his younger brother Ferdinand over to the Moroccans as a hostage for the delivery of Ceuta. It was later reported that Henry personally volunteered to go as hostage instead of Ferdinand, but that his war council