Louis the Younger (830/835 – 20 January 882), crowned Louis III] was the second eldest of the three sons of Louis II the German. He succeeded his father as the King of Saxony on 28 August 876 and his elder brother Carloman as King of Bavaria from 880 to 882. He died in 882 and was succeeded by his younger brother, Charles the Fat, already King of Italy and Emperor.
Louis III, the Younger (r.)
As a young man, Louis was deployed in military operations against the Abodrites to the east in 858 and 862. In 854, at the invitation of the nobles of Aquitaine opposed to Charles the Bald and Pepin II, and coaxed by his father and his cousin Charles, Archbishop of Mainz, he crossed into Gaul at the head of an army, intent on receiving the crown of Aquitaine. He marched as far as Limoges before turning back.
At home, Louis forged close ties with the nobles of the East Francia and became increasingly independent from his father. In 865, he and his brother Charles joined in rebellion against their father. The "revolt" was brief, however, and Louis, Charles, and their father were reconciled later that year. The division of territories was now made definite as Louis received Saxony, Thuringia, and Franconia and Charles Alemannia and Rhaetia.
In 869, Louis married Luitgard, daughter of Liudolf, Duke of Eastphalia, at Aschaffenburg. Luitgard was a strong-willed and politically ambitious woman and later on spurred her husband to pursue ambitious goals. This match increased dissension between father and son and in 871 and in 873, Louis rebelled, but each time he was reconciled.
Rule in Saxony
Upon his father's death in 876, Louis fully inherited the title Rex Francorum ("king of the Franks"). Louis the Younger considered himself the true heir of Louis the German and as his father died in 876, Louis buried him in the abbey of Lorsch, in his own territories, in order to emphasise his primacy to his brothers. Louis also retained his father's chief advisor, Luitbert, Archbishop of Mainz. He and his brother ruled their kingdoms independently but cooperatively.
Acquisition of Lotharingia and Bavaria
Louis's rule was immediately threatened by Charles the Bald, who tried to annex the eastern parts of Lotharingia and attempted to achieve supremacy over his nephew. Louis brought war on Charles and, on 8 October 876 at Andernach, he defeated the much larger host of West Francia. The East Frankish army displayed superiority in both unity and tactics, his soldiers dressed in white garments appeared as an army of dead spirits.
After this victory, Louis the German's three sons met in November at Nördlingen to discuss the division of their father's kingdom and to have their hosts swear allegiance. According to the plan drawn up in 865, Carloman received Bavaria, Charles Swabia, and Louis Saxony, Franconia, and Thuringia. Throughout his reign, though Louis is always called "King of Saxony" by historians, he never visited Saxony proper, though it formed the bulk of his territory. At the end of 877, the brothers assembled again to discuss the administration of their half of Lotharingia.
Following the death of Charles the Bald in November 878, his successor, Louis the Stammerer promised to respect the agreements made in 865 and 877. Known as the Treaty of Fouron, this was soon put to the test, when Louis the Stammerer died in April 879. A party of nobles and church dignitaries invited Louis the Younger to succeed to the rule of the western kingdom. Marching toward Verdun, the new kings Louis III and Carloman offered their part of Lotharingia to Louis. He retreated and in February 880, his gains were confirmed by the Treaty of Ribemont. This treaty determined the border of the two kingdoms that were to remain unchanged until the fourteenth century.
Since the summer of 879, Vikings had been increasing their attacks on the Frankish kingdom and occasionally penetrated deeply into the interior of the land. Louis's kingdom was the most hard-hit after that of West Francia. In February 880, Louis confronted and defeated a Norse host at the Battle of Thimeon (near modern Charleroi) and drove the Norse out of Nijmegen. Despite these victories, a Saxon host commanded by Duke Bruno, suffered a heavy defeat near Hamburg. As Thimeon illustrates, no single military victory could stop the tide of Viking incursions.
Death and succession
Louis fell sick in 881 and died in Frankfurt on 20 January 882. He was buried beside his father in the abbey of Lorsch. Since he left no heir, all his territories fell to his brother Charles, who thus could reunite the entire East Frankish kingdom.