Walter Map (c. 1137 – 1209) was a medieval writer, probably either of Welsh origin or from Herefordshire (which at the time was almost the same thing). He was of noble birth, and acted as a clerk to King Henry II of England, later becoming chancellor of Lincoln, canon of St Paul's and archdeacon of Oxford. His only surviving work, De Nugis Curialium (Trifles of the Court) is a collection of anecdotes and trivia, containing court gossip and a little real history, and written in a satirical vein. He has been considered to be the author of a prose romance of Lancelot, and was alleged to have written a quantity of Goliardic poetry.
Map, along with William of Newburgh, recorded the earliest stories of English Vampires.