Charlemagne conquered more German territory and secured the eastern frontier. By means of military campaigns and missionary activities he brought Saxony and northern Frisia under control; the Saxons, led by Widukind, offered a protracted resistance (772–804), and Charlemagne either destroyed or forcibly deported a large part of the population. To the south, Bavaria was brought under Frankish authority and annexed. Conquests in the east brought the Carolingians into contact with new peoples—Charlemagne was able to defeat the Avars in three campaigns (791, 795, 796), from which he obtained considerable booty; he was also able to establish a march on the middle Danube, and the Carolingians undertook the conversion and colonization of that area. Charlemagne established the Elbe as a frontier against the northern Slavs. The Danes constructed a great fortification, the Danewirk, across the peninsula to stop Carolingian expansion. Charlemagne also founded Hamburg on the banks of the Elbe. These actions gave the Franks a broad face on the North Sea.
The Frankish state was now the principal power in the West. Charlemagne claimed to be defender of Roman Christianity and intervened in the religious affairs of Spain. Problems arose over doctrinal matters that, along with questions concerning the Italian border and the use of the imperial title, brought him into conflict with the Byzantine Empire; a peace treaty was signed in 810–812. Charlemagne continued his peace policy toward the Muslim East: ambassadors were exchanged with the caliph of Baghdad, and Charlemagne received a kind of eminent right in Jerusalem. The restoration of the empire
When by the end of the 8th century Charlemagne was master of a great part of the West, he reestablished the empire in his own name. He was crowned emperor in Rome on Christmas Day, 800, by Pope Leo III, who had been savagely attacked by rivals in Rome in 799 and who hoped that the restoration of an imperial authority in western Europe would protect the papacy. Charlemagne’s powers in Rome and in relation to the Papal States, which were incorporated, with some degree of autonomy, into the Frankish empire, were clarified. Although his new title did not replace his royal titles, it was well suited to his preponderant position in the old Roman West. The imperial title, later known as Holy Roman emperor, indicates a will to unify the West; nevertheless, in his succession plan of 806, Charlemagne preserved the kingdom of Italy, giving the crown to one of his sons, Pippin, and made Aquitaine a kingdom for his other son, Louis. The continuing dispute with the Byzantines over the imperial title may have led to his reluctance to pass it on, or, more likely, he saw it as a personal honour in recognition of his great achievements. Louis I
Only chance ensured that the empire remained united under Louis I (the Pious), the last surviving son of Charlemagne. Louis was crowned emperor in 813 by his father, who died the following year. The era of great conquests had ended, and, on the face of it, Louis’s principal preoccupation was his relationship with the peoples to the north. In the hope of averting the threat posed by the Vikings, who had begun to raid the coasts of the North Sea and the Atlantic Ocean, Louis proposed to evangelize the Scandinavian world. This mission was given to St. Ansgar but was a failure.
During Louis’s reign, the imperial bureaucracy was given greater uniformity. Louis the Pious saw the empire, above all, as a religious ideal, and in 816 in a separate ceremony the pope anointed him and crowned him emperor. At the same time, Louis took steps to regulate the succession so as to maintain the unity of the empire (Ordinatio Imperii, 817). His eldest son, Lothar I, was to be sole heir to the empire, but within it three dependent kingdoms were maintained: Louis’s younger sons, Pippin and Louis, received Aquitaine and Bavaria, respectively; his nephew Bernard was given Italy. He also replaced the dynasty’s customary relationship with the pope with the Pactum Hludowicianum in 817, which clearly defined relations between the two in a way that favoured the emperor.
The remarriage of Louis the Pious to Judith of Bavaria and the birth of a fourth son, who would rule as Charles II (the Bald), upset this project. In spite of opposition from Lothar, who had the support of a unity faction drawn from the ranks of the clergy, the emperor sought to create a kingdom for Charles the Bald. These divergent interests would undermine Louis’s authority and cause much civil strife. Notably, in 830 Louis faced a revolt by his three older sons, and in 833–834 he confronted a second, more serious revolt. In 833 he was abandoned by his followers on the Field of Lies at Colmar and then deposed and forced by Lothar to do public penance. Judith and Charles were placed in monasteries. Lothar, however, overplayed his hand and alienated his brothers, who restored their father to the throne. Lothar lived in disgrace until a final reconciliation with his father near the end of Louis’s life. The partitioning of the Carolingian empire The Treaty of Verdun
After the death of Louis the Pious (840), his surviving sons continued their plotting to alter the succession. Louis II (the German) and Charles II (the Bald) affirmed their alliance against Lothar I with the Oath of Strasbourg (842). After several battles, including the bloody one at Fontenoy, the three brothers came to an agreement in the Treaty of Verdun (843). The empire was divided into three kingdoms arranged along a north-south axis: Francia Orientalis was given to Louis the German, Francia Media to Lothar, and Francia Occidentalis to Charles the Bald. The three kings were equal among themselves. Lothar kept the imperial title, which had lost much of its universal character, and the imperial capital at Aix-la-Chapelle (now Aachen, Germany).
The Carolingian empire and (inset) divisions after the Treaty of Verdun, 843.Encyclopædia Britannica, Inc.
The kingdoms created at Verdun
Until 861 the clerical faction tried to impose a government of fraternity on the descendants of Charlemagne, manifested in the numerous conferences they held, but the competition of the brothers and their supporters undermined clerical efforts.
Francia Media proved to be the least stable of the kingdoms, and the imperial institutions bound to it suffered as a result. In 855 the death of Lothar I was followed by a partition of his kingdom among his three sons: the territory to the north and west of the Alps went to Lothar II (Lotharingia) and to Charles (kingdom of Provence); Louis II received Italy and the imperial title. At the death of Charles of Provence (863), his kingdom was divided between his brothers Lothar II (Rhône region) and Louis II (Provence). After the death of Lothar II in 869, Lotharingia was divided between his two uncles, Louis the German and Charles the Bald. Louis, however, did not gain control of his share until 870. Charles was made master of the Rhône regions of the ancient kingdom of Provence, while Louis turned most of his attention to fighting the Muslims who threatened the peninsula and the papal territories.
In Francia Occidentalis Charles the Bald was occupied with the struggle against the Vikings, who ravaged the countryside along the Scheldt, Seine, and Loire rivers. More often than not, the king was forced to pay for their departure with silver and gold. Aquitaine remained a centre of dissension. For some time (until 864) Pippin II continued to have supporters there, and Charles the Bald attempted to pacify them by installing his sons—first Charles the Child (reigned 855–866) and then Louis II (the Stammerer; 867–877)—on the throne of Aquitaine. The problems in Aquitaine were closely connected to general unrest among the magnates, who wished to keep the regional king under their control. By accumulating countships and creating dynasties, the magnates succeeded in carving out large principalities at the still unstable borders: Robert the Strong and Hugh the Abbot in the west; Eudes, son of Robert the Strong, in this same region and in the area around Paris; Hunfred, Vulgrin, Bernard of Gothia, and Bernard Plantevelue (Hairyfoot), count of Auvergne, in Aquitaine and the border regions; Boso in the southeast; and Baldwin I in Flanders. Nevertheless, Charles the Bald appeared to be the most powerful sovereign in the West, and in 875 Pope John VIII arranged for him to accept the imperial crown. An expedition he organized in Italy on the appeal of the pope failed, and the magnates of Francia Occidentalis rose up. Charles the Bald died on the return trip (877). Charles’s son Louis the Stammerer ruled for only two years. At his death in 879 the kingdom was divided between his sons Louis III and Carloman. In the southeast, however, Boso, the count of Vienne, appropriated the royal title to the kingdom of Provence. The imperial throne remained vacant. The death of Louis III (882) permitted the reunification of Francia Occidentalis (except for the kingdom of Provence) under Carloman.