Charles the Bald and Louis the German defeated Emperor Lothar I at Fontenoy, a major turning point in the Carolingian civil war that accelerated negotiations toward partition and weakened the prospect of renewed unified rule.
Louis the German and Charles the Bald publicly swore mutual oaths at Strasbourg, solidifying their coalition against Lothar I and signaling the emergence of distinct political-linguistic blocs within the former empire.
The Treaty of Verdun divided the empire among Lothar I (middle kingdom plus imperial title), Louis the German (eastern kingdom), and Charles the Bald (western kingdom). This institutionalized regional kingship and set the political framework for later fragmentation and noble autonomy.
Charles the Bald issued the Edict of Pîtres, ordering measures against Viking raids and mobilizing mounted forces. The pressure of external attacks and local defense needs strengthened regional leaders and contributed to the growing importance of local military power.
The death of Robert the Strong—key Neustrian magnate—during fighting against Breton-Viking forces underscored how frontier warfare elevated regional war leaders. His family’s subsequent prominence illustrates how military leadership could translate into durable regional authority.
After Lothar II died without a legitimate heir, Louis the German and Charles the Bald divided Lotharingia by treaty. The rearrangement of the middle kingdom reinforced the pattern of negotiated partitions and further destabilized central Carolingian control over border regions.
Before departing for Italy, Charles the Bald issued the Capitulary of Quierzy to safeguard governance and manage appointments during his absence. Traditionally linked to the growth of hereditary officeholding, it reflects how royal reliance on magnates could entrench regional power.
Bishops and nobles in the Rhône–Saône region elected Boso as king in Lower Burgundy/Provence, a striking assertion of regional elite choice beyond direct Carolingian succession. This marked a further step in the political fragmentation of Carolingian authority.
West Frankish kings Louis III and Carloman II reached agreement with Louis the Younger of East Francia, recognizing East Frankish control over Lotharingia. The settlement hardened the west–east division and reduced West Frankish influence in the contested middle zone.
Vikings besieged Paris from late 885 to 886. The city’s defense under Duke Odo highlighted the ability of powerful regional leaders to act where royal power faltered, setting the stage for greater noble leverage in West Francia.
East Frankish magnates deposed Emperor Charles the Fat in November 887 and elevated Arnulf of Carinthia. The deposition ended the last major reunion of Carolingian rule and encouraged separate kingdoms and regional power centers to pursue their own rulers.
Arnulf of Carinthia won a major victory over Vikings near Leuven on the Dyle River. Continued external threats and the need for rapid regional mobilization reinforced the role of local aristocracies and commanders in defense and governance.
Arnulf installed his son Zwentibold as king in Lotharingia, effectively delegating rule over a strategically sensitive region. The move illustrates how reliance on sub-kings and regional elites could further loosen centralized authority.
Charles the Simple negotiated with the Viking leader Rollo, granting land in return for loyalty and defense—foundational for the Duchy of Normandy. This exemplified the shift toward localized, negotiated power arrangements as Carolingian resources and authority waned.
Rise of Regional Nobility and the Fragmentation of Carolingian Authority (840–920)
