Background
The Carolingian Empire, established by Charlemagne, was one of the most powerful entities in medieval Europe. Upon Charlemagne’s death in 814, his son Louis the Pious inherited the empire. However, Louis’s reign was marked by internal strife and external threats, which weakened the empire’s cohesion. The situation deteriorated further after Louis’s death in 840, leading to a series of conflicts among his sons — Lothair I, Louis the German, and Charles the Bald.
Prelude to the Treaty
Throughout his long reign, Louis the Pious endeavored to divide his empire fairly among all his sons, as mandated by the Salic Law of the Franks. However, the birth of his youngest son, Charles, led to civil wars. These conflicts culminated in 839 with Louis’s decisive victory over his rebellious son, Louis. On May 30 of that year, at Worms, he made his final division of the empire: Lothair retained Italy and the imperial title, Charles received the western lands, and Louis was left with Bavaria. Pepin, his grandson, was excluded from the inheritance.
On July 24, 840, in Strasbourg, Lothair sparked a new civil war by claiming authority over the entire empire and, with his nephew Pepin, attacked the Loire Valley. The Burgundian barons were split in their loyalties: Ermenaud III of Auxerre, Arnoul of Sens, and Audri of Autun supported Lothair, while Guerin of Provence and Aubert of Avallon sided with Charles. Girard II, Count of Paris and Lothair’s son-in-law, also joined Lothair. In March 841, the Burgundians loyal to Charles joined Guerin, and in May, Louis of Bavaria and his troops met Charles’s army at Châlons-sur-Marne. By June, Pepin had finally allied with Lothair in Auxerre.
Battle of Fontenoy (841)
The two armies clashed on June 25. Tradition holds that Charles set up his camp at Thury, on the hill of Roichat. Lothair and Pepin began the battle and initially gained the upper hand until Guerin and his Provençal forces arrived. While Pepin’s troops continued to push back Charles’s men, Lothair was gradually driven back by Louis the German and the Provençals. When victory seemed assured for Charles, Bernard of Septimania joined the fray on his side, turning the victory into a rout. According to Andreas Agnellus of Ravenna, 40,000 men perished, including Gerard of Auvergne and Ricwin of Nantes, who fought alongside Charles.
Despite his personal bravery, Lothair was defeated and fled to his capital, Aachen. With fresh troops, he launched a campaign of plunder, but his brothers’ united forces were too strong. Gathering what treasure he could, he abandoned his capital to them.
The Treaty of Verdun
After nearly three years of continuous warfare, the warring brothers recognized the futility of further conflict and agreed to negotiate a settlement. The Treaty of Verdun, signed in August 843, divided the Carolingian Empire into three distinct kingdoms:
- West Francia: Charles the Bald received the western portion of the empire, which roughly corresponds to modern-day France.
- East Francia: Louis the German was granted the eastern portion, encompassing much of present-day Germany.
- Middle Francia: Lothair I retained the central portion, including the imperial title and lands stretching from the North Sea to Italy.
The Treaty of Verdun set the stage for future military conflicts and alliances in medieval Europe. The division of the Carolingian Empire created a power vacuum that various regional powers sought to exploit. Some of the long-term military consequences included:
- Feudal Fragmentation: The decentralization of power led to the rise of feudalism, where local lords wielded significant military and political authority. This fragmentation made it difficult to mobilize large, unified armies, leading to a reliance on smaller, localized forces.
- Border Conflicts: The new borders established by the treaty were often contested, leading to frequent skirmishes and wars between the kingdoms. The struggle for control over strategic regions such as Lorraine and Burgundy became a recurring theme in medieval European warfare.
- Viking Raids: The weakened and divided Carolingian Empire became a prime target for Viking raiders. The inability to present a unified defense allowed the Vikings to conduct devastating raids along the coasts and rivers of West Francia and East Francia.
The Treaty of Verdun in 843 was a landmark event that reshaped the political and military landscape of medieval Europe. The division of the Carolingian Empire set the stage for the development of the modern nations of France and Germany, while also contributing to the rise of feudalism and the persistent threat of Viking incursions.
