Henry IV ( April 1367 – 20 March 1413), also known as Henry Bolingbroke, was King of England from 1399 to 1413. His grandfather King Edward III had claimed the French throne as a grandson of Philip IV of France, and Henry continued this claim. He was the first English ruler since the Norman Conquest, over three hundred years prior, whose mother tongue was English rather than French. Henry was the son of John of Gaunt, Duke of Lancaster, himself the son of Edward III. John of Gaunt was a power in England during the reign of his own nephew, Richard II. Henry was involved in the revolt of the Lords Appellant against Richard in 1388, resulting in his exile. After Gaunt died in 1399, Richard blocked Henry's inheritance of his father's duchy. That year, Henry rallied a group of supporters, overthrew and imprisoned Richard II, and usurped the throne, actions that later would lead to what is termed the Wars of the Roses and a more stabilized monarchy. As king, Henry faced a number of rebellions, most seriously those of Owain Glyndŵr, the self-proclaimed ruler of Wales, and the English knight Henry Percy (Hotspur), who was killed in the Battle of Shrewsbury in 1403. The king suffered from poor health in the latter part of his reign, and his eldest son, Henry of Monmouth, assumed the reins of government in 1410. Henry IV died in 1413, and his son succeeded him as King Henry V. Early life Henry was born at Bolingbroke Castle, in Lincolnshire, to John of Gaunt and Blanche of Lancaster. His epithet "Bolingbroke" was derived from his birthplace. Gaunt was the third son of King Edward III. Blanche was the daughter of the wealthy royal politician and nobleman Henry, Duke of Lancaster. Gaunt enjoyed a position of considerable influence during much of the reign of his own nephew, King Richard II. Henry's elder sisters were Philippa, Queen of Portugal, and Elizabeth, Duchess of Exeter. His younger half-sister, the daughter of his father's second wife, Constance of Castile, was Katherine, Queen of Castile. He also had four natural half-siblings born of Katherine Swynford, originally his sisters' governess, then his father's longstanding mistress and later third wife. These illegitimate children were given the surname Beaufort from their birthplace at the Château de Beaufort in Auvergne-Rhône-Alpes, France. Henry's relationship with his stepmother, Katherine Swynford, was a positive one, but