[2] Fernando de Castro was a member of the royal council of John I of Portugal, and was appointed by him as governor of the household of Prince Henry the Navigator.
Realizing, too late, that he had not brought along sufficient supplies for so many troops on the beach (water could only be obtained inland), Fernando de Castro decided to cancel the expedition and returned to Portugal.
Despite his connection with the Canaries enterprise, in 1432, Fernando de Castro was sent to Castile again on another diplomatic mission – this time, to witness the ratification of the 1431 peace treaty.
It was around this time (1434) that Fernando de Castro also served as regedor in the Casa do Cível (lower court of appeals) in Lisbon.
In order to preserve his army from destruction, Henry the Navigator negotiated a treaty to restore Ceuta to Morocco, handing over his own brother, Ferdinand the Saint Prince to the Marinids as a hostage, until the terms were fulfilled.
As it turns out, the Portuguese Cortes refused to ratify the treaty, preferring to retain Ceuta and leave Ferdinand in Moroccan captivity.
But around 1440, disregarding the Cortes, the new Portuguese regent Peter of Coimbra decided to fulfill the treaty nonetheless, and swap Ceuta for his imprisoned brother.
In the meantime, an embassy under Gomes Eanes and Martim de Távora was to proceed to Asilah to receive the released Ferdinand from the strongman Abu Zakariya Yahya al-Wattasi, governor of the Marinid palace of Fez (called Lazeraque by the Portuguese chroniclers).
It is said that Fernando de Castro openly fantasized that the released Infante Ferdinand might marry his own daughter, and prepared a rich and well-stocked expedition, packing the ships with banquet finery, an entourage of notables, and a bodyguard of some 1200 troops.