Henry IV (15 April 1367 – 20 March 1413) was King of England and Lord of Ireland from 1399 to 1413 and asserted the claim of his grandfather, Edward III, to the Kingdom of France. He was born at Bolingbroke Castle in Lincolnshire, hence his other name, Henry of Bolingbroke /ˈbɒlɪŋbrʊk/. His father, John of Gaunt, was the third son of Edward III, and enjoyed a position of considerable influence during much of the reign of Henry's cousin Richard II, whom Henry eventually deposed. Henry's mother was Blanche, heiress to the considerable Lancaster estates, and thus he became the first King of England from the Lancaster branch of the Plantagenets.

Siblings

One of Henry's elder sisters, Philippa of Lancaster, married John I of Portugal, and the other, Elizabeth, was the mother of John Holland, 2nd Duke of Exeter. His younger half-sister Catherine, the daughter of his father's second wife, Constance of Castile, was queen consort of Castile. He also had four half-siblings by Katherine Swynford, originally his sisters' governess, then his father's longstanding mistress, and later his third wife. These four children were given the surname Beaufort after a castle their father held in Champagne, France.