Fernando de Noronha was appointed to Ceuta only days before a Portuguese expeditionary force, led by Henry the Navigator, was defeated by the army of Marinid Morocco (see Battle of Tangier (1437)).
By several accounts, Fernando de Noronha was determined not to lose this lucrative perch (his predecessor had made a substantial personal fortune from ransoms and pirate kickbacks.)
Noronha probably had a role in stiffening Henry's resolve to write to King Edward from Ceuta, recommending the Portuguese renege on the treaty he had himself signed.
In 1440, after Edward died and Peter became regent of the realm, ambassadors were dispatched to Asilah to negotiate the logistics of the swap of Ceuta for the captive Ferdinand.
Peter agreed, and in April 1440 (or 1441), he dispatched D. Fernando de Castro at the head of a Portuguese flotilla, with instructions and credentials to take the city from Noronha, and begin the evacuation of the garrison.
Nonetheless, Peter of Coimbra hurriedly instructed Fernando's son, Álvaro de Castro, to take over his father's credentials and fulfill the mission.