Humphrey (IV) de Bohun (1208 or bef. 1208 – 24 September 1275) was 2nd Earl of Hereford and 1st Earl of Essex, as well as Constable of England. He was the son of Henry de Bohun, 1st Earl of Hereford and Maud of Essex. He was one of the nine godfathers of Prince Edward, later to be Edward I of England. He served as High Sheriff of Kent for 1239–1240.
After returning from a pilgrimage to the Holy Land, he was one of the writers of the Provisions of Oxford in 1258. The Provisions of Oxford are often regarded as England's first written constitution (although the Magna Carta and earlier law codes such as that of King Ethelbert of Kent are also significant). Vincent, Nicholas (2004). "Bohun, Humphrey (IV) de, second earl of Hereford and seventh earl of Essex (d. 1275)". Oxford Dictionary of National Biography