Map of Treaty of Mersen
New divisions of the empire corresponding to France, Germany, and Italy.
37. When Lothaire died (855) he left Italy and the middle kingdom to his three sons. By 870 two of these had died, and their uncles, Charles the Bald and Louis the German, did not hesitate to appropriate the middle kingdom and divide it between them by the treaty of Mersen. Italy was left to Lothaire's only surviving son, together with the imperial crown, which was to mean nothing, however, for a hundred years to come. The result was that, as early as 870, western Europe was divided into three great districts which corresponded with startling exactness to three important states of modern Europe, i.e., France, Germany, and Italy.
The empire temporarily reunited under Charles the Fat.
Louis the German was succeeded in the East-Frankish kingdom by his son, Charles the Fat. In 884, owing to the death of the sons and the grandsons of Charles the Bald, there was no one to represent his line except a child of five years. So the aristocracy of the West-Frankish kingdom invited Charles the Fat to become their king. In this way it came about that the whole empire of Charlemagne was reunited for two or three years under a single ruler.[55]
Charles the Fat and the Northmen.
Charles the Fat was ill and proved an incompetent emperor, entirely unequal to the serious task of governing and protecting his vast territories. His weakness was especially shown in his pusillanimous treaties with the Northmen. When Paris was making an heroic defense against them under its count, Odo, Charles, instead of marching at the head of an army to relieve it, agreed to pay the invaders seven hundred pounds of silver if they would raise the siege. They were then permitted to take up their winter quarters far inland, in Burgundy, where they proceeded to burn and pillage at will.
Charles the Fat deposed and succeeded by Arnulf.
This degrading agreement so disgusted the West-Frankish nobility that they were glad to join a conspiracy set on foot by Charles' nephew, the brave Arnulf of Carinthia, who had resolved to supplant his inefficient uncle. Charles was deposed and deserted by all his former supporters in 887. No one, except Napoleon, has ever again succeeded in bringing the eastern, western, and southern parts of Charlemagne's empire under his control, even for a brief period. Arnulf, although enjoying the title of emperor, could scarcely hope to be recognized as king in all parts of the Frankish empire. Even nominal unity was no longer possible. As one of the chronicles of the time puts it, "While Arnulf was frittering away his time, many little kingdoms grew up."