In 881, Charles the Fat was crowned emperor while Louis III of Saxony and Louis III of Francia died the following year. Saxony and Bavaria were united with Charles the Fat's Kingdom, and Francia and Neustria were granted to Carloman of Aquitaine who also conquered Lower Burgundy. Carloman died in a hunting accident in 884 after a tumultuous and ineffective reign, and his lands were inherited by Charles the Fat, effectively recreating the empire of Charlemagne.

Charles, suffering what is believed to be epilepsy, could not secure the kingdom against Viking raiders, and after buying their withdrawal from Paris in 886 was perceived by the court as being cowardly and incompetent. The following year his nephew Arnulf of Carinthia, the illegitimate son of King Carloman of Bavaria, raised the standard of rebellion. Instead of fighting the insurrection, Charles fled to Neidingen and died the following year in 888, leaving a divided entity and a succession mess.