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
Succession to the French throne a dynastic struggle between the House of Plantagenet and the House of Valois for control of the French throne. The conflict, known as the Hundred Years War, dragged on for decades. England won several famous military victories, but was unable to fully overcome French resistance. Yet in the aftermath of the Battle of Agincourt, Henry V of England, great-grandson of Edward III, became the heir to the French throne in accordance to the Treaty of Troyes. He would marry Catherine, daughter of King Charles VI of France, while Charles' son, the Dauphin Charles was declared illegitimate and disinherited. Yet Henry