John of Gaunt, Duke of Lancaster 1340-99
English prince

Born in Ghent, Flanders, the fourth (but third surviving) son of Edward III, he married his cousin, Blanche of Lancaster (1359), and was created duke (1362). His son by Blanche became Henry IV. After Blanche died (1369), he married (1372) Constance, daughter of Pedro the Cruel of Castile, and assumed the title of King of Castile, though he failed in his expeditions to oust his rival, Henry of Trastamare. Reserved, haughty and conventional, in England he was the most influential person during the reign of his father, and was thought to be aiming at the Crown. He was largely responsible for crushing the Peasants' Revolt (1381). He opposed the clergy and protected John Wycliffe. Edward's successor, Richard II, distrusting him, sent him on another attempt to secure a treaty for the marriage of his daughter Catherine to the future King of Castile (1386). After his return to England (1389) he became an influential peacemaker, was made Duke of Aquitaine by Richard (1394), and went on several embassies to France. On his second wife's death (1394) he married his mistress, Catherine Swynford (1396), by whom he had three sons, legitimized in 1397, from the eldest of whom Henry VII of England was descended.

Bibliography: S Armitage-Smith, John of Gaunt (1904)