Earldom of Pembroke: His [Gilbert's] son the 2nd Earl of Pembroke ("Strongbow") was instigator of the Anglo-Norman/Cambro-Norman incursion into Ireland in 1169 or 1170. Pembroke himself managed to subdue Leinster. His daughter and ultimately heiress married William (the) Marshal, who was created Earl of Pembroke in 1199 by King John, though he may already have had some kind of status as Earl of Pembroke in right of his wife. [Burke's Peerage]