Marie of Boulogne
Marie was the daughter of Stephen of England and Matilda of Boulogne.  She was placed in a convent when she was young so that she could become a nun.  When her brother, William of Blois, died, she became the heir of the Count of Boulogne.  She had to leave the convent and was married to Matthew of Alsace.  Marie and Matthew ruled Boulogne together, but their marriage was not happy and they got a divorce in 1170.