Henry VI of England in accordance with the Treaty of Troyes of 1420, he became titular King of France upon his grandfather Charles VI's death. His mother, Catherine of Valois, was then 20 years old. As Charles VI's daughter, she was viewed with considerable suspicion by English nobles and was prevented from playing a full role in her son's upbringing. On 28 September 1423, the nobles swore loyalty to Henry VI. They summoned Parliament in the King's name and established a regency council to govern until the King should come of age. One of Henry V's surviving brothers, John, Duke of Bedford, was appointed
Henry IV of England his nephew King Richard II (1377-1399) whom Henry eventually deposed. Henry's mother was Blanche of Lancaster, heiress to the great Lancashire estates of her father Henry of Grosmont, 1st Duke of Lancaster (a descendant in the male line of King Henry III). Henry, having succeeded his father as 2nd Duke of Lancaster, when he became king thus founded the Lancaster branch of the Plantagenet English monarchy. He was also the first King of England since the Norman Conquest whose mother tongue was English rather than French. One of Henry's elder sisters, Philippa of Lancaster, married King John I of Portugal,