Peter, Duke of Coimbra
After King John I's death in 1433, John's eldest brother ascended the throne as king Edward of Portugal. In 1437, Infante John joined another brother Peter, Duke of Coimbra, in arguing against a projected Portuguese expedition to seize Tangier that led to the Battle of Tangier. The campaign ended in disaster. After the Tangier fiasco, John urged the ratification of a treaty with Marinid Morocco that called for the relinquishment of Ceuta in exchange for his captive brother Ferdinand the Holy Prince. The Cortes refused, and Ferdinand was left to die in captivity.