Honorius was also called to intervene in the affairs of Normandy, as Fulk of Anjou and King Henry I of England battled for domination. Henry objected to the marriage of Fulk's daughter Sibylla of Anjou to William Clito, the son of the duke of Normandy, on the grounds that they were too closely related by blood, being sixth cousins. They refused to divorce, and Honorius was forced to excommunicate Fulk and his son-in-law and to impose an interdict upon their territories.