He was the son of Humphrey de Bohun and Margaret, daughter of Henry, Earl of Huntingdon, a son of David I of Scotland. His paternal grandmother was Margaret, daughter of Milo of Gloucester, Earl of Hereford and Constable of England.
The male line of Milo of Gloucester having failed, on the accession of King John of England, de Bohun was created Earl of Hereford and Constable of England (1199).
De Bohun was one of the 25 executors of the Magna Carta. He married Maud, daughter of Geoffrey Fitz Piers, Earl of Essex, and was succeeded by his son Humphrey de Bohun, 2nd Earl of Hereford.