Humphrey (VI) de Bohun, 3rd Earl of Hereford and 2nd Earl of Essex, was an English nobleman known primarily for his opposition to King Edward I over the Confirmatio Cartarum. He was also an active participant in the Welsh Wars and maintained for several years a private feud with the earl of Gloucester. His father, Humphrey (V) de Bohun, fought on the side of the rebellious barons in the Barons' War. When Humphrey (V) predeceased his father, Humphrey (VI) became heir to his grandfather, Humphrey (IV). At Humphrey (IV)'s death in 1275, Humphrey (VI) inherited the earldoms of Hereford and Essex. He also inherited major possessions in the Welsh Marches from his mother, Eleanor de Braose.

Gilbert de Clare, 6th Earl of Hertford, 7th Earl of Gloucester was a powerful English noble. He was also known as "Red" Gilbert de Clare or "The Red Earl", probably because of his hair colour or fiery temper in battle. He held the Lordship of Glamorgan which was one of the most powerful and wealthy of the Welsh Marcher Lordships as well as over 200 English manors.