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, King of England daughter and heiress of Humbert III of Savoy. As part of this agreement John was promised the future inheritance of Savoy, Piedmont, Maurienne, and the other possessions of Count Humbert. For his part in the potential marriage alliance, Henry II transferred the castles of Chinon, Loudun and Mirebeau into John's name; as John was only five years old his father would continue to control them for practical purposes. Henry the Young King was unimpressed by this; although he had yet to be granted control of any castles in his new kingdom, these were effectively his future property and had been