Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Isabel de Clare, suo jure Countess of Pembroke and Striguil (1172 1220), was a Cambro-Norman-Irish noblewoman and one of the greatest heiresses in Wales and Ireland. She was the wife of William Marshall, 1st Earl of Pembroke (1146 14 May 1219).