In 836, Lothair, in his role as king of the Lombards, began stripping the possessions of the Roman church. After appealing to Louis, the emperor sent an imperial envoy to investigate the matter. Although Gregory was sick, he managed to advise the envoy of the situation, and asked him to take a letter to the emperor outlining Lothair’s attacks on the Church, which they managed to get past Lothair’s troops at Bologna. Then in 840, with Louis’ death and the accession of Lothair as emperor, war again erupted between the sons of Louis. Gregory made unsuccessful attempts to mediate in the conflict that ensued between the brothers, sending Archbishop George of Ravenna as his representative. According to Prudentius of Troyes, George faithfully tried to achieve his objective, but failed due to Lothair’s refusal to allow George to see Lothair’s brothers. However, according to Andreas Agnellus, George tried to bribe Lothair to make his archbishopric independent of Rome, and was captured at the Battle of Fontenoy. The subsequent Treaty of Verdun in 843 broke up the empire of Charlemagne, with Lothair retaining the imperial title and control of Italy.