Ranulf Flambard (sometimes Ralph Flambard, Ranulph Flambard, or Ranulf Passiflamme; c. 1060 – 5 September 1128) was a medieval Norman Bishop of Durham and an influential government minister of King William Rufus of England. Ranulf was the son of a priest of Bayeux, Normandy, and his nickname Flambard means incendiary or torch-bearer, and may have referred to his personality. He started his career under King William I of England, probably in the compilation of the Domesday Book, as well as being the keeper of the king's seal. On the death of William I, Ranulf chose to serve the new king of England, William Rufus.