Lothair Ii. or III. (c. 1070-1137), surnamed the “Saxon,” Roman emperor, son of Gebhard, count of Supplinburg, belonged to a family possessing extensive lands around Helmstadt in Saxony, to which he succeeded on his father’s death in 1075. Gebhard had been a leading opponent of the emperor Henry IV. in Saxony, and his son, taking the same attitude, assisted Egbert II., margrave of Meissen, in the rising of 1088. The position and influence of Lothair in Saxony, already considerable, was increased when in 1100 he married Richenza, daughter of Henry, count of Nordheim, who became an heiress on her father’s death in 1101, and inherited other estates when her brother Otto died childless in 1116. Having assisted the German king, Henry V., against his father in 1104, Lothair was appointed duke of Saxony by Henry, when Duke Magnus, the last of the Billungs, died in 1106. His first care was to establish his authority over some districts east of the Elbe; and quickly making himself independent of the king, he stood forth as the representative of the Saxon race. This attitude brought him into collision with Henry V., to whom, however, he was forced to submit after an unsuccessful rising in 1112. A second rising was caused when, on the death of Ulrich II., count of Weimar and Orlamünde, without issue in 1112, Henry seized these counties as vacant fiefs of the empire, while Lothair supported the claim of Siegfried, count of Ballenstädt, whose mother was a relative of Ulrich. The rebels were defeated, and Siegfried was killed at Warnstädt in 1113, but his son secured possession of the disputed counties. After the defeat by Lothair of Henry’s forces at Welfesholz on the 11th of February 1115, events called Henry to Italy; and Lothair appears to have been undisturbed in Saxony until 1123, when the death of Henry II., margrave of Meissen and Lusatia raised a dispute as to the right of appointment to the vacant margraviates. A struggle ensued, in which victory remained with the duke. The Saxony policy of Lothair during these years had been to make himself independent, and to extend his authority; to this end he allied himself with the papal party, and easily revived the traditional hostility of the Saxons to the Franconian emperors.
When Henry V. died in 1125, Lothair, after a protracted election, was chosen German king at Mainz on the 30th of August 1125. His election was largely owing to the efforts of Adalbert, archbishop of Mainz, and the papal party, who disliked the candidature of Henry’s nephew and heir, Frederick II. of Hohenstaufen, duke of Swabia. The new king was crowned at Aix-la-Chapelle on the 13th of September 1125. Before suffering a severe reverse, brought about by his interference in the internal affairs of Bohemia, Lothair requested Frederick of Hohenstaufen to restore to the crown the estates bequeathed to him by the emperor Henry V. Frederick refused, and was placed under the ban. Lothair, unable to capture Nüremberg, gained the support of Henry the Proud, the new duke of Bavaria, by giving him his daughter, Gertrude, in marriage, and that of Conrad, count of Zähringen, by granting him the administration of the kingdom of Burgundy, or Arles. As a counterstroke, however, Conrad of Hohenstaufen, the brother of Frederick, was chosen German king in December 1127, and was quickly recognized in northern Italy. But Lothair gained the upper hand in Germany, and by the end of 1129 the Hohenstaufen strongholds, Nüremberg and Spires, were in his possession. This struggle was accompanied by disturbances in Lorraine, Saxony and Thuringia, but order was soon restored after the resistance of the Hohenstaufen had been beaten down. In 1131 the king led an expedition into Denmark, where one of his vassals had been murdered by Magnus, son of the Danish king, Niels, and where general confusion reigned; but no resistance was offered, and Niels promised to pay tribute to Lothair.
The king’s attention at the time was called to Italy where two popes, Innocent II. and Anacletus II., were clamouring for his support. At first Lothair, fully occupied with the affairs of Germany, remained heedless and neutral; but in March 1131 he was visited at Liége by Innocent, to whom he promised his assistance. Crossing the Alps with a small army in September 1132, he reached Rome in March 1133, accompanied by Innocent. As St Peter’s was held by Anacletus, Lothair’s coronation as emperor took place on the 4th of June 1133 in the church of the Lateran. He then received as papal fiefs the vast estates of Matilda, marchioness of Tuscany, thus securing for his daughter and her Welf husband lands which might otherwise have passed to the Hohenstaufen. His efforts to continue the investiture controversy were not very serious. He returned to Germany, where he restored order in Bavaria, and made an expedition against some rebels in the regions of the lower Rhine. Resuming the struggle against the Hohenstaufen, Lothair soon obtained the submission of the brothers, who retained their lands, and a general peace was sworn at Bamberg. The emperor’s authority was now generally recognized, and the annalists speak highly of the peace and order of his later years. In 1135, Eric II., king of Denmark, acknowledged himself a vassal of Lothair; Boleslaus III., prince of the Poles, promised tribute and received Pomerania and Rügen as German fiefs; while the eastern emperor, John Comnenus, implored Lothair’s aid against Roger II. of Sicily.
The emperor seconded the efforts of his vassals, Albert the Bear, margrave of the Saxon north mark, and Conrad I., margrave of Meissen and Lusatia, to extend the authority of the Germans in the districts east of the Elbe, and assisted Norbert, archbishop of Magdeburg, and Albert I., archbishop of Bremen, to spread Christianity. In August 1136, attended by a large army, Lothair set out upon his second Italian journey. The Lombard cities were either terrified into submission or taken by storm; Roger II. was driven from Apulia; and the imperial power enforced over the whole of southern Italy. A mutiny among the German soldiers and a breach with Innocent concerning the overlordship of Apulia compelled the emperor to retrace his steps. An arrangement was made with regard to Apulia, after which Lothair, returning to Germany, died at Breitenwang, a village in the Tirol, on the 3rd or 4th of December 1137. His body was carried to Saxony and buried in the monastery which he had founded at Königslutter. Lothair was a strong and capable ruler, who has been described as the “imitator and heir of the first Otto.” Contemporaries praise his justice and his virtue, and his reign was regarded, especially by Saxons and churchmen, as a golden age for Germany.
The main authorities for the life and reign of Lothair are: “Vita Norberti archiepiscopi Magdeburgensis”; Otto von Freising, “Chronicon Annalista Saxo” and “Narratio de electione Lotharii” all in the Monumenta Germaniae historica. Scriptores, Bände vi., xii. and xx. (Hanover and Berlin, 1826-1892). The best modern works are: L. von Ranke, Weltgeschichte, pt. viii. (Leipzig, 1887-1888); W. von Giesebrecht, Geschichte der Deutschen Kaiserzeit, Band iv. (Brunswick, 1877), Band v. (Leipzig, 1888); Ph. Jaffe, Geschichte des Deutschen Reiches unter Lothar (Berlin, 1843); W. Bernhardi, Lothar von Supplinburg (Leipzig, 1879); O. von Heinemann, Lothar der Sachse und Konrad III. (Halle, 1869); and Ch. Volkmar, “Das Vërhältniss Lothars III. zur Investiturfrage,” in the Forschungen zur Deutschen Geschichte, Band xxvi. (Göttingen, 1862-1886).