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 the face of threats of secession by the Gascon nobles. He was one of England's principal negotiators in the diplomatic exchanges with France that led to the Truce of Leulingham in 1396, and he initially agreed to join the French-led Crusade that ended in the disastrous Battle of Nicopolis, but withdrew due to ill-health and the political problems in Gascony and England. For the remainder of his life, John of Gaunt occupied the role of valued counsellor of the king and loyal supporter of the Crown. He did not even protest, it seems, when his younger brother Thomas was murdered