What type of surety was the Earl of Pembroke who participated in the battle at Lincoln castle in 1217?
William Marshal, 2nd Earl of Pembroke William Marshal, 2nd Earl of Pembroke (French:"Guillaume") (1190 – 6 April 1231) was a medieval English nobleman and was one of Magna Carta sureties. He fought during the First Barons' War and was present at the Battle of Lincoln (1217).
William de Ferrers, 4th Earl of Derby William II de Ferrers, 4th Earl of Derby (c. 1168 – c. 1247) was a favourite of King John of England. He succeeded to the estate (but not the title) upon the death of his father, William de Ferrers, 3rd Earl of Derby, at the Siege of Acre in 1190. He was head of a family which controlled a large part of Derbyshire which included an area known as Duffield Frith.