Henry IV (April 1367 – 20 March 1413), also known as Henry Bolingbroke, was King of England from 1399 to 1413. He asserted the claim of his grandfather King Edward III, a maternal grandson of Philip IV of France, to the Kingdom of France. Henry 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, and grandson of Edward III. John of Gaunt was a power in England during the reign of Henry's cousin Richard II. Henry was involved in the revolt of the Lords Appellant against Richard in 1388. Henry was later exiled by Richard. After John 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.

More Info: en.wikipedia.org