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).
John FitzRobert John FitzRobert (ca. 1190 - 1240) (de Clavering) is listed as one of the Surety Barons in Magna Carta (1215) where he is described as Lord of Warkworth Castle.