John of Gaunt of Castile. As his father and elder brother, Edward, the Black Prince, became incapacitated due to poor health, Gaunt assumed control of many government functions, and rose to become one of the most powerful political figures in England. He was faced with military difficulties abroad and political divisions at home, and disagreements as to how to deal with these crises led to tensions between Gaunt, the English Parliament, and the ruling class, making him an extremely unpopular figure for a time. John exercised great influence over the English throne during the minority of King Richard II, and the ensuing periods
John of Gaunt Castilians refused to offer battle and the Galician-Anglo-Portuguese troops, apart from time-wasting sieges of fortified towns, were reduced to foraging for food in the arid Spanish landscape. They were harried mainly by French mercenaries of the Castilian king. Many hundreds of English, including close friends and retainers of John of Gaunt, died of disease or exhaustion. Many deserted or abandoned the army to ride north under French safe-conducts. Shortly after the army returned to Portugal, John of Gaunt concluded a secret treaty with John of Trastámara under which he and his wife renounced all claim to the Castilian throne in