Original: Since she was the heiress to the county of Boulogne , she was forced to leave her convent and married off to Matthew of Alsace ( c.1130-1173 ) , who would become Count of Boulogne and co-ruler (/O1160/O) through his marriage to her .
Simplified: Marie and Matthew ruled Boulogne together , but their marriage was not happy and they got a divorce in 1170 .