Roger I of Tosny Fécamp Abbey were installed. This monastery was one of the first baronial foundations in Normandy The foundation charter reveals that the lord of Tosny gave it a small possession around Conches and his forest. In 1035, Robert I's death began a troubled period in the duchy of Normandy. Civil wars multiplied and Roger (whose relations with his neighbours was already argumentative) was one of the main players in them. According to the Norman chroniclers, the lord of Tosny refused to serve the new duke, the future William the Conqueror, due to his being a bastard. He especially took advantage of
William the Conqueror of the year on which fighting was permitted. Although the Battle of Val-ès-Dunes marked a turning point in William's control of the duchy, it was not the end of his struggle to gain the upper hand over the nobility. The period from 1047 to 1054 saw almost continuous warfare, with lesser crises continuing until 1060. William's next efforts were against Guy of Burgundy, who retreated to his castle at Brionne, which William besieged. After a long effort, the duke succeeded in exiling Guy in 1050. To address the growing power of the Count of Anjou, Geoffrey Martel, William joined with