Introduction: fraternal rivalry, 840–843

The deposition of Louis the Pious in 833 was neither, we have seen, the definitive disaster of the emperor's own reign nor of the Carolingian empire writ large. Still, the Frankish political community was unmistakably shocked. The main protagonists harboured anxieties about what they had done: in a letter of 847, the emperor Lothar reflected almost disbelievingly on that time of conflict between him and his brothers as ‘the work of the Devil through his agents’. But even the traumas of the early 830s were eclipsed in the Frankish psyche by the three years of bloody civil war which followed the death of Louis the Pious in 840. Once again, his sons were at the heart of the matter. A loose alliance of Charles the Bald and Louis the German teamed up against Lothar and Pippin II of Aquitaine (the three kings’ nephew who was hoping to dislodge Charles from the south-west and claim the kingdom of his father Pippin I, who had died in 838). As their armies ceaselessly roamed the empire in a game of armed chess whose top prize was control of the Carolingian heartlands in the north, a long series of armed stand-offs and skirmishes peaked at the bloody battle of Fontenoy in June 841. (See Map 14 for places mentioned in this chapter.) A man called Engelbert, who fought on Lothar's side, later wrote a poem lamenting the extreme violence and horrifying implications of the battle: ‘No slaughter was ever worse on any field of war…This battle is not worthy of praise, not fit to be sung.’

Major pitched battles were rare in the early medieval period precisely because so much could hinge on their outcome; and recent history, even the dark days of the early 830s, provided few examples of noble Franks drawing swords in earnest against their comrades. The Franks were thus stunned by the loss of aristocratic life at Fontenoy. Four decades later in a work written for the emperor Charles the Fat, Notker of St Gallen recoiled from even mentioning the name of the battle, so horrified was he that Christian blood had been spilled by Louis the German, Charles's father. A few years before that, Pope John VIII had taunted the same Louis by reminding him of the ‘still-damp fields of Fontenoy that he soaked with human blood in his youth’. All four Carolingians survived the fighting and in this sense the battle was not decisive. However, victory for Charles and Louis gave them the edge and effectively undermined Lothar's prospects of winning the war as a whole. His forays into the western strongholds of Charles, and those of Louis in the east, became less and less convincing and he was forced to negotiate. The final seal was set on the truce in summer 843 by the famous Treaty of Verdun. This carefully planned division split the empire into three vertical strips, with Charles receiving the western portion, Lothar the middle, and Louis the eastern – Pippin II, like Pippin the Hunchback and Bernard of Italy before him, was airbrushed out of the family picture.