Ceuta. King John I of Portugal was a popular ruler who defeated neighboring Castile in 1411 and temporarily ended a long string of wars between Portugal and Castile. He had a politically beneficial marriage to Philippa of Lancaster, the daughter of John of Gaunt, with whom he had six children: Edward, Pedro, Henry, Isabel, John, and Ferdinand. In 1414, the three oldest sons were at the age to make a name for themselves on the battlefield, but Castile was no longer a threat. Instead, they planned an attack on the North African city of Ceuta, a Moorish city strategically located south of the Straits of Gibraltar at the western entrance to the Mediterranean Sea. The plan was based in part on youthful pursuit of adventure, greed for the wares of Ceuta, and a crusading mentality that encouraged Christians to attack the Muslims...