William Marshal, 2nd Earl of Pembroke

William Marshal, 2nd Earl of Pembroke (French: Guillaume le Maréchal) (1190 – 6 April 1231) was a medieval English nobleman and was one of the sureties of Magna Carta.

Due to his support of Aedh Ua Conchobair against Richard de Burgh in their claims to Connacht, he was dismissed as Justicar, surrendering office to the king at Winchester on 22 June 1226.

Due to his continued support, he was later that year ordered to surrender to the crown the custody of the royal castles of Cardigan and Carmarthen which he had captured from Llywelyn.

In February 1231 William also returned to England, and arranged the marriage of his sister Isabel, widow of Gilbert de Clare, to Richard, Earl of Cornwall, brother of King Henry III.

William was responsible for the commissioning of L'Histoire de Guillaume le Mareschal, the first known biography of a medieval knight, in order to record his father's extraordinary career.

His lack of male heirs was credited to a curse bestowed upon the family by the Bishop of Ferns, Ailbe Ua Maíl Mhuaidh.

All of William's brothers inherited the title successively, but as the Bishop predicted, none had children and the male line of the family died out on the death of Anselm Marshal in 1245.

Arms of William Marshal, 2nd Earl of Pembroke, drawn by Matthew Paris : Party per pale or and vert, a lion rampant gules . These arms were later adopted in 1269 in lieu of his own paternal arms by Roger Bigod, 5th Earl of Norfolk (1245–1266) on his inheritance of the office of Marshal of England from the Marshal family