LOUIS (804-876), surnamed "the German," king of the East Franks, was the third son of the emperor Louis I. When the emperor divided his dominions between his sons in 817, Louis re ceived Bavaria and the neighbouring lands, but did not under take the government until 825, when he began to fight the Slays on his eastern frontier. In 827 he married Emma, daughter of Welf I., count of Bavaria, and sister of his stepmother Judith. He interfered in the quarrels arising from Judith's efforts to secure a kingdom for her own son Charles, and the consequent struggles of Louis and his brothers with the emperor Louis I. (q.v.). When the elder Louis died in 84o and his eldest son Lothair claimed the whole Empire, Louis in alliance with his half-brother, king Charles the Bald, defeated Lothair at Fontenoy on June 25, 841. By the Treaty of Verdun (August 843), Louis received the bulk of the lands of the Carolingian empire lying east of the Rhine, in cluding a district around Speyer, Worms and Mainz, Bavaria, where he made Regensburg the centre of his government, Thuringia, Franconia and Saxony.
Louis may truly be called the founder of the German kingdom, though his attempts to maintain the unity of the Empire proved futile. In 842 he crushed a rising in Saxony, compelled the Abotrites to own his authority, and undertook campaigns against the Bohemians, the Moravians and other tribes. He did not suc ceed in freeing his shores from the ravages of Danish pirates. At his instance synods and assemblies were held where laws were decreed for the better government of church and state. From 853 onwards, he attempted to secure the throne of Aquitaine, offered to him by the oppressed subjects of Charles the Bald. But treachery and desertion in his army, and the loyalty of the Aquitanian bishops to Charles prevented success, and Louis re nounced his claim by a treaty signed at Coblenz on June 7, 86o. In 855 the emperor Lothair died, and was succeeded in Italy by his eldest son Louis II., and in the northern part of his kingdom by his second son, Lothair. The weakness of these kingdoms afforded opportunities for intrigue by Louis and Charles the Bald, whose interest was increased by the fact that both their nephews were without male issue. Louis supported Lothair in his efforts to divorce his wife Teutberga, for which he received a promise of Alsace, but in 865 Louis and Charles renewed the peace of Coblenz, and doubtless discussed the possibility of dividing Lo thair's kingdom. In 868 at Metz they agreed definitely to a
partition; but when Lothair died in 869, Louis was ill, and his armies were engaged with the Moravians. Charles the Bald ac cordingly seized the whole kingdom; but Louis compelled him by a threat of war to agree to the Treaty of Mersen, which divided it between the claimants.
The later years of Louis were troubled by risings on the part of his sons, the eldest of whom, Carloman, revolted in 861 and in 863 ; an example followed by the second son Louis, who in a further rising was joined by his brother Charles. A report that Louis II. was dead led to peace between father and sons. The emperor, however, was not dead, but a prisoner; and as he was the nephew and son-in-law of Louis, that monarch hoped to se cure both the imperial dignity and the Italian kingdom for his son Carloman. Meeting his daughter Engelberga, the wife of Louis II., at:Trent in 872, Louis made an alliance with her against Charles the Bald, and in 874 visited Italy on the same errand. The emperor, having named Carloman as his successor, died in August 875, but Charles the Bald reached Italy before his rival, and by persuading Carloman to return, secured the imperial crown. Louis was preparing for war when he died on Sept. 28, 876 at Frankfort. He was in war and peace alike, the most com petent of the descendants of Charlemagne. He obtained for his kingdom a certain degree of security against the Normans, Hun garians, Moravians and others. He lived in close alliance with the Church, to which he was very generous, and supported its mis sionary schemes.
See Annales Fuldenses; Annales Bertiniani; Nithard, Historiarum Libri, all in the Monumenta Germaniae historica. Scriptores, Bde i. and ii. (Hanover and Berlin, 1826 seq.) ; E. Diimmler, Geschichte des ostfrankischen Reiches (Leipzig, 1887-88) ; Sickel, Die Urkunden Ludwigsi des Deutschen (Vienna, 1861-62) ; E. Miihlbacher, Die Regesten des Kaiserreichs enter den Karolingern (Innsbruck, 1880 ; and A. Krohn, Ludwig der Deutsche (Saarbriicken, 1872) ; and general bibliography in Camb. Med. Hist. (vol. 3, 1922) .