English nobleman; son of Humphrey VII de Bohun. One of the lords ordainers who attempted to curb the powers of Edward II in 1310, he took part in the execution (1312) of the hated Piers Gaveston. He fought for Edward at Bannockburn (1314), was captured by the Scots, and was exchanged. He was killed at Boroughbridge fighting on the baronial side against the king and the Despensers.

He was the 4th Earl of Hereford and the 3rd Earl of Essex. He was also the Lord High Constable of England. He married November 14, 1302, at Westminster, Princess Elizabeth Plantagenet, widow of John, Count of Holland and Zealand, and daughter of King Edward I. of England and Eleanor of Castile, daughter of King Ferdinand III. of Leon and Castile in Spain. In the 30th year of King Edward I, he gave and granted unto the king, by formal conversance, the inheritance of all his lands and lordships, as also of his earldoms of Hereford and Essex, and the constableship of England, which, upon his marriage with Elizabeth Plantaganet, widow of John, Earl of Holland, and daughter of the king, were regranted to him, and entailed upon his issue lawfully begotten by that lady; in default thereof, and from and after the death of himself and his wife, then the lordship Plassets, and certain other lordships in Essex, and elsewhere. together with the constableship, should remain wholly to the king and his heirs for ever. In the 34th year of the same reign he had a grant similarly entailed of the whole territory of Annadale, in Scotland.
After this he was in the wars of Scotland and was taken prisoner, in the 7th year of King Edward II. (1313-1314), at the disastrous battle (to the English) of Stryvelin. But he was exchanged for the wife of Robert Bruce, who had long been captive in England. From this period we find him constantly engaged in the service of the crown, until the 14th year of the king's reign, when Edward learning that the earl was raising forces in the marches of Wales, against Hugh Despencer the Younger, sent him a peremptory command to forbear, which he not only refused obeying, but forthwith joined Thomas, Earl of Lancaster, in the great insurrection then incited by that nobleman, for the redress of certain grievances, and the banishment of the Spencers. In this proceeding, however, he eventually lost his life, being run through the body by a soldier at the battle of Boroughbridge, in Yorkshire, where his party received so signal a defeat on March 16, 1321.
He joined the barons in opposition to Edward's favorites, Piers de Gaveston and the Despencers. He assisted in the execution of Piers de Gaveston in 1312, for which he was pardoned in 1313. He fought at Bannockburn and was taken prisoner at Bethwell on June 24, 1314, where he had retreated, having been betrayed by the Governor, Sir Walter Gilbertson. He was then exchanged for Elizabeth, wife of Robert Bruce, King of Scotland, who had been a prisoner for some time. On February 11, 1315 or 1316 he was appointed captain of all the forces against Llewellyn Bran in the land of Glamorgan. Summoned to attend the Council at Gloucester, he sent word that he would not do so while Hugh Despencer, the younger, was in the king's comtive. He was then ordered to attend at Oxford, and preparing to attack the said Despencer was ordered on May 1, 1321, to abstain, but during May and June the lands of Despencer were ravaged. In accordance with an agreement in parliament, he received a pardon August 20, 1321. Bohun was killed at Boroughbridge on March 16, 1321 or 1322 when endeavoring to force the bridge. He was buried in the church of the Friars Preachers at York