diocese. Liudolf's Civil War Rebellion against Otto With the humiliating failure of his Italian campaign and Otto's marriage to Adelaide, Liudolf became estranged from his father and planned a rebellion. On Christmas Day 951, he held a grand feast at Saalfeld that was attended by many important figures from across the kingdom, most notably Archbishop Frederick of Mainz, the Primate of Germany. Liudolf was able to recruit his brother-in-law Conrad, Duke of Lorraine, to his rebellion. As Otto's regent in Italy, Conrad had negotiated a peace agreement and an alliance with Berengar II and believed that Otto would confirm this treaty. Instead of an ally, Berengar II was made Otto's subject and his kingdom was subsequently reduced. Conrad felt betrayed and insulted over Otto's decision, especially with the additional empowerment of Henry. Conrad and Liudolf viewed Otto as being controlled by his foreign-born wife and power-hungry brother and resolved to free the kingdom from their domination. In winter 952, Adelaide gave birth to a son, whom she named Henry after her brother-in-law and the child's grandfather, Henry the Fowler. Rumors spread that Otto had been persuaded by his wife and brother to propose this child as his heir instead of Liudolf. For many German nobles, this rumor represented Otto's final transformation from a policy focused on Germany to an Italian-centered one. The idea that Otto would ask them to revoke the succession rights of Liudolf prompted many nobles into open rebellion. Liudolf and Conrad first led the nobles against Henry, the Duke of Bavaria, in spring 953. Henry was unpopular with the Bavarians due to his Saxon heritage, and his vassals quickly rebelled against him. Word of the rebellion reached Otto at Ingelheim. In order to secure his position, he traveled to his stronghold at Mainz. The city was also the seat of Archbishop Frederick of Mainz, who acted as mediator between Otto and the rebels. Recorded details of the meeting or the negotiated treaty do not exist, but Otto soon left Mainz with a peace treaty favorable to the conspirators, most likely confirming Liudolf as heir apparent and approving Conrad's original agreement with Berengar II. These terms rendered the treaty incompatible with the wishes of Adelaide and Henry. When Otto returned to Saxony, Adelaide and Henry persuaded the king to void the treaty. Convening the Imperial Diet at Fritzlar, Otto declared Liudolf and Conrad as outlaws in absentia. The