Edmund of Langley, 1st Duke of York, English politician, Lord Warden of the Cinque Ports (d. 1402)

Edmund of Langley, 1st Duke of York, KG (5 June 1341 – 1 August 1402) was the fourth surviving son of King Edward III of England and Philippa of Hainault. Like many medieval English princes, Edmund gained his nickname from his birthplace: Kings Langley Palace in Hertfordshire. He was the founder of the House of York, but it was through the marriage of his younger son, Richard of Conisburgh, 3rd Earl of Cambridge, to Anne de Mortimer, great-granddaughter of Edmund's elder brother Lionel of Antwerp, 1st Duke of Clarence, that the House of York made its claim to the English throne in the Wars of the Roses. The other party in the Wars of the Roses, the incumbent House of Lancaster, was formed from descendants of Edmund's elder brother John of Gaunt, 1st Duke of Lancaster, Edward III's third son.