John of Gaunt John of Gaunt John of Gaunt, Duke of Lancaster (6 March 13403 February 1399) was an English prince, military leader, and statesman. He was the third of the five sons of King Edward III of England who survived to adulthood. Due to his royal origin, advantageous marriages, and some generous land grants, Gaunt was one of the richest men of his era, and an influential figure during the reigns of both his father, Edward, and his nephew, Richard II. As Duke of Lancaster, he is the founder of the royal House of Lancaster, whose members would ascend to the throne
English claims to the French throne as King of France, but with his new son-in-law King Henry V of England as his heir (disinheriting Charles VI's son, the Dauphin Charles). Henry V then adopted the title Heir of France instead. Henry V and Charles VI died within two months of each other in 1422, and Henry V's infant son (Charles VI's grandson) Henry VI became King of France. He was the only English king who was "de facto" King of France, rather than using the style as a mere title of pretense. However, by 1429 Charles VII, with the support of Joan of Arc, had been