The empire of Charlemagne did not long remain intact. So vast was its extent and so unlike were its inhabitants in race, language, and customs that it could be managed only by a ruler of the greatest energy and strength of will. Unfortunately, the successors of Charlemagne proved to be too weak for the task of maintaining peace and order. Western Europe now entered on a long period of confusion and violence, during which Charlemagne's possessions broke up into separate and warring kingdoms.

TREATY OF VERDUN, 843 A.D.

Charlemagne's son, Louis the Pious, who became emperor in 814 A.D., was a well-meaning but feeble ruler, better fitted for the quiet life of a monastery than for the throne. He could not control his rebellious sons, who, even during his lifetime, fought bitterly over their inheritance. The unnatural strife, which continued after his death, was temporarily settled by a treaty concluded at the city of Verdun. According to its terms Lothair, the eldest brother, received Italy and the imperial title, together with a narrow stretch of land along the valleys of the Rhine and the Rhone, between the North Sea and the Mediterranean. Louis and Charles, the other brothers, received kingdoms lying to the east and west, respectively, of Lothair's territory. The Treaty of Verdun may be said to mark the first stage in the dissolution of the Carolingian Empire.

TREATY OF MERSEN, 870 A.D.

A second treaty, made at Mersen in Holland, was entered into by Louis and Charles, after the death of their brother Lothair. They divided between themselves Lothair's kingdom north of the Alps, leaving to his young son the possession of Italy and the empty title of "emperor." The Treaty of Mersen may be said to mark the second stage in the dissolution of the Carolingian Empire. That empire, as such, had now ceased to exist.

[Illustration: Map, THE FRANKISH DOMINIONS AS DIVIDED BY THE TREATIES OF
VERDUN (843 A.D.) AND MERSEN (870 A.D.)]

IMPORTANCE OF THE TWO TREATIES

The territorial arrangements made by the treaties of Verdun and Mersen foreshadowed the future map of western Europe. The East Frankish kingdom of Louis, inhabited almost entirely by Germanic peoples, was to develop into modern Germany. The West Frankish kingdom of Charles, inhabited mainly by descendants of Romanized Gauls, was to become modern France. Lothair's kingdom, separated into two parts by the Alps, never became a national state. Italy, indeed, might be united under one government, but the long, narrow strip north of the Alps had no unity of race, no common language, and no national boundaries. It was fated to be broken into fragments and to be fought over for centuries by its stronger neighbors. Part of this territory now forms the small countries of Belgium, Holland, and Switzerland, and another part, known as Alsace and Lorraine, [17] still remains a bone of contention between France and Germany.

RENEWED BARBARIAN INVASIONS

Even had Charlemagne been followed by strong and able rulers, it would have been a difficult matter to hold the empire together in the face of the fresh series of barbarian inroads which began immediately after his death. The Mohammedans, though checked by the Franks at the battle of Tours, [18] continued to be dangerous enemies. They ravaged southern France, Sicily, and parts of Italy. The piratical Northmen from Denmark and Norway harried the coast of France and made inroads far beyond Paris. They also penetrated into western Germany, sailing up the Rhine in their black ships and destroying such important towns as Cologne and Aix-la- Chapelle. Meanwhile, eastern Germany lay exposed to the attacks of the Slavs, whom Charlemagne had defeated but not subdued. The Magyars, or Hungarians, were also dreaded foes. Their wild horsemen entered Europe from the plains of Asia and, like the Huns and Avars to whom they were probably related, spread devastation far and wide. A great part of Europe thus suffered from invasions almost as destructive as those which had brought ruin to the old Roman world.