On June 16, 870, Hincmar of Laon was called to the Synod of
Attigny where Charles instructed Hincmar to renew his oath to his uncle. Hincmar was reluctant but eventually the pressure of the king and the archbishop was successful. At Attigny more accusations of a similar ilk to 868 were brought against Hincmar. Two days later, on June 18th, there was a royal tribunal. Two of Hincmar's men – Ragenardus and Grivo – accused him of
expropriation. In his defence Hincmar asserted that the witnesses who knew the truth of what happened were not present, yet Charles forced him to answer. As a result, Hincmar accused both Ragenardus and Grivo of wrongdoing yet he was unable to substantiate these claims or back them up under oath. Fearing imprisonment, Hincmar fled back to Laon. This fear was not without basis, yet was an irrational and self-destructive move. Following the death of Lothar II in August 869 there is evidence linking Hincmar to the conspiracy of
Carloman. Carloman was son of Charles the Bald who from an early age was excluded from inheriting his father's crown. Following Lothar's death, he was able to gather an aristocratic following in Lotharingia and vie in a grab for power around 870. Both Peter McKeon and Janet Nelson subscribe to the view that Hincmar was sympathetic to Carloman. The timings of Hincmar's renewed oaths, the backing of the pope to both Hincmar and Carloman, and both men's connections to Lotharingia offer a ‘tantalising persistent thread.’ While Nelson admits that none of the charges against Hincmar mention complicity with Carloman the timings of events ‘seem more than a coincidence.’ Only two days after Hincmar swore allegiance at Attingy (June 16) Carloman was arrested by Charles (June 18) and taken to the stronghold of
Senlis. In 871 Hincmar of Rheims drew up a Synodal document to excommunicate Carloman and cease his grab for power. Hincmar of Laon's refusal to endorse this document proved to be a desperate and final act of defiance.‘Already embroiled in major disputes with both his uncle and Charles the Bald, and already suspected of conspiring with Lothar II, Hincmar of Laon now brought down on himself the full extent of the king’s wrath.’In August 871 Hincmar was seized by royal agents at taken to
Douzy where he appeared before an ecclesiastical court. Charles summoned eight archbishops and twenty-two bishops to preside over the
Synod of Douzy. At Douzy Hincmar was deposed from episcopal and priestly rank. Pope Hadrian II attempted to intervene but Charles the Bald was successful in defending royal rights within his realm, and following his death in 872 the most powerful dissenting voice to the deposition of Hincmar was removed. Carloman was retried and blinded in 873, permanently ending his attempts to be king. Later in the year Hincmar of Laon was also blinded, by order of
Count Boso. Nelson states that by doing this, Charles the Bald ‘took vengeance for what he clearly believed was continued complicity with Carloman.’ Despite the decision reached at the Synod of Douzy it was not until 876, and with the permission of
Pope John VIII that Archbishop Hincmar ordained his nephew's successor, Hedenulf, to the see of Laon. == Final years ==