The Abbey of Saint-Étienne was founded by a descendant of who?
William the Conqueror William I (c. 1028 – 9 September 1087), usually known as William the Conqueror and sometimes William the Bastard, was the first Norman King of England, reigning from 1066 until his death in 1087. A descendant of Rollo, he was Duke of Normandy (as Duke William II) from 1035 onward. After a long struggle to establish his power, by 1060 his hold on Normandy was secure, and he launched the Norman conquest of England six years later. The rest of his life was marked by struggles to consolidate his hold over England and his continental lands and by difficulties with his eldest son.
Matthew, Count of Boulogne Matthew, Count of Boulogne, also known as "Matthew of Alsace" (  1137 –1173) was the second son of Thierry, Count of Flanders and Sibylla of Anjou. Matthew forcibly abducted the nun Marie de Boulogne, daughter of Stephen, King of England, and constrained her into marriage, claiming the title of Count of Boulogne "jure uxoris" in 1160. The forced marriage was opposed by the Church and finally annulled in 1170, but he continued to rule as Count until his death.