Earl William Marshal of Pembroke ¹

William married Isabel de Clare of Pembroke, daughter of Earl Richard de Clare of Pembroke 2nd (Strongbow) and Aoife (Eva) MacMurrough. (Isabel de Clare of Pembroke was born in 1172 in Pembroke Castle, Pembrokeshire, England and died in 1220.)

William next married Countess Eleanor Plantagenet of Pembroke, daughter of King John Plantagenet of England (Lackland) and Isabella of Angoulême, on 23 Apr 1224. (Countess Eleanor Plantagenet of Pembroke was born in 1215 in Gloucester, , GLS, ENG and died on 13 Apr 1275 in Montargis, France.)