Louis the Younger

Louis's rule was immediately threatened by Charles the Bald, who tried to annex the eastern parts of Lotharingia and maybe even 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, and the young king had even dressed his soldiers in white garments so that they appeared as an army of 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, which their father, despite all his sons' rebellions, had confirmed in 872, Carloman received Bavaria, Charles Swabia, and Louis Saxony, Franconia, and Thuringia. Throughout his reign, though he 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. After Carloman relinquished his claim, the realm was divided between Louis and Charles, who again met in September 878 in Alsatia. In 879, Carloman was incapacitated by a stroke and named Louis as his successor (and erstwhile regent) in Bavaria. Louis received it outright a year later when Carloman expired.

In November 878, after the death of Charles the Bald, his heir, Louis the Stammerer, and the latter's cousin Louis the Younger promised each other to respect the succession of their respective sons and to issue no claims contrary to that, at Voeren (Fourons in French). This Treaty of Fouron was soon put to the test, when Louis the Stammerer died in April 879. A party of western nobles led by Abbot Joscelin invited Louis the Younger to succeed to the rule of the western kingdom. Since his wife Liutgard also advocated heeding this call, Louis invaded West Francia. He marched as far as Verdun, but after the new kings Louis III and Carloman ceded their part of Lotharingia to the invader, Louis retreated. In February 880, this gain was confirmed by the Treaty of Ribemont, signed near Saint Quentin. This treaty determined the border of the two kingdoms, which was to remain unchanged until the fourteenth century.

In contrast to his father, Louis the Younger preferred reconciling royal interests with those of the nobility and avoided confrontation. He managed to bind powerful families to the king, including the Liudovingian relatives of his wife, that later themselves became kings and emperors. Louis mostly stayed in the Rhineland, avoiding Saxony or his eastern borders. Louis did visit Bavaria on two occasions, but mostly left it to the government of his illegitimate nephew, Carloman's son, Arnulf, Duke of Carinthia.[6]

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).[7] His son Hugh, however, was killed in this battle.[7] The next year, Louis III, King of West Francia, defeated the Norse at the battle of Saucourt.[8] Louis the Younger also drove the Norse out of the royal palace of Nijmegen, which they had occupied. In the same month, a Saxon host commanded by Duke Bruno, the king's brother-in-law, suffered a heavy defeat near Hamburg and Bruno and many other Saxon nobles fell.