Lothair II (c. 837 — 7 August 869) was the king of Lotharingia from 855 until his death. He is known for his over ten-year-long divorce case with his wife Teutberga so that he could remarry his long-standing lover Waldrada. Lothair began a relationship with Waldrada in his adolescence. By the time of his accession in September 855, he seems to have still loved her. However, the king was forced to marry Teutberga of the Bosonids and ally with her brother Hucbert to maintain his position. Lothair put away Teutberga as Hucbert's importance waned, but after she passed a trial by ordeal he was forced to take her back. Hucbert died in revolt in 864 after being replaced in Lothair's court.
In 858, Louis the German unsuccessfully invaded West Francia, but Lothair helped negotiate a peace between Louis and Charles the Bald by June 860. He was able to act as a mediator between his kingly uncles. Lothair convened his first council at Aachen in that year, in which he was divorced from Teutberga. Charles broke the peace in 861, but by 862 Lothair had allied with Louis the German and again held the upper hand. Lothair convened the second Aachen council in that year which allowed him to marry Waldrada and made peace with Charles in November. Lothair's brother, Charles of Provence died in 863 and Lothair partitioned Lower Burgundy with his elder brother, Emperor Louis. Pope Nicholas I suddenly undermined Lothair's position and excommunicated two of his archbishops, and some Lotharingian bishops sought the pope's forgiveness. Nicholas was able to force Lothair to remarry Teutberga by 865. In 867, Nicholas died, and his successor Adrian II was more flexible. Lothair went to Rome in 869 to meet with him, but died on the return trip.
Lothair issued less coinage than his father and significantly fewer charters than Charles the Bald, although his chancery remained functional. Lothair's dealings with the Northmen were focused on Rorik of Dorestad, a Viking leader in Frisia. In 863, Lothair attacked and chased a Norse raiding party, but did not destroy them. Lothair won a significant victory against Rorik in 867 and inflicted heavy casualties.
Lothair's grandfather was Louis the Pious, who has been crowned as emperor by his father, Charlemagne, in 813. In 817, at Aachen, Louis crowned his eldest son Lothair I co-emperor and heir to the Carolingian Empire. Louis' planned division of the empire became impossible after the birth of his youngest son, Charles the Bald, and conflict between father and sons began in 829. Lothair and his brothers, Pepin and Louis the German, ambushed Louis and took over the imperial government. Pepin and Louis the German were promised a larger share of the inheritance, and thus turned on Lothair, ending the revolt.
A second revolt broke out in 833, prompted by Louis taking Aquitaine from Pepin and granting it to Charles. Lothair turned his father's supporters away from him and took over the government, capturing Louis, his wife Judith, and Charles. Infighting broke out amongst Lothair's supporters, allowing him to be deposed and the emperor to be freed. Lothair and his men defeated Louis' supporters, led by Wido, who had been dispatched to drive them out from the Breton March. Shortly afterwards, Lothair captured Châlons, but before making more progress he was defeated by the emperor with Louis the German in battle and forced to make peace.
Conflicts between father and son recommenced from 837 to 839, although Lothair remained loyal, and they were quickly defeated. After Louis' death in 840, a civil war broke out between the sons. In 841, Louis was defeated at the Battle of Fontenoy, but by 843, at the Treaty of Verdun, peace was signed. Lothair married Ermengarde of Tours in 821, and with her he had three sons. The eldest was, Louis II, born around 825. About a decade later came Lothair II, and the third son was Charles of Provence. According to a later, possibly erroneous account written by Bishop Adventius of Metz, Lothair II had been wed by his father to Waldrada in the early 850s.
Mortally ill, Lothair's father, Lothair I, divided his realm between his sons. Louis II, the eldest, held Italy and the imperial title since 850; Lothair II, about 18 years old, was given Lothair I's territory between Frisia and the Alps, while Charles, still a child, received Lower Burgundy. Lothair I died on 19 September. The young Lothair initially had custody of his brother Charles. Lothair was brought by his magnates to the court of his uncle, Louis the German, at Frankfurt, so that Louis could confirm him as king. In exchange, he probably ceded Alsace to Louis, in expectation that the young Charles could be made to step aside. In the event, this did not happen and Louis did not permanently acquire Alsace.
Although confirmed by Louis, Lothair's position was still insecure, and to establish himself as king he was forced to marry the daughter of Boso the Elder, Teutberga, securing the support of her brother Hucbert. The Bosonids and their relations were part of a ruling class which held connections and properties throughout the whole Frankish world whose families commanded great wealth, enough to present a danger to kings and transfer their support. For Lothair, he could not yet act independently. Lothair nearly came to blows with his brother Louis, but with the intervention of the magnates Lothair I's division was maintained at the Treaty of Orbe and by late 856 Lothair was more well-established. His accession was confirmed by the king's anointment. Rabanus Maurus, the archbishop of Mainz, wrote for Lothair at his accession a moral and military treatise, De procinctu romanae miliciae, tailored to his young age.
Marriage issue and Hucbert's revolt
At his accession Lothair had already had multiple children by his boyhood mistress, Waldrada, whom he seems to have still loved. Hucbert's position declined; not only was he considered a "violent, aggressive, and sexually debauched individual," but after the Treaty of Orbe his strategic usefuleness and political value diminished greatly. By late 856, Hucbert's standing at court was already waning. Lothair renewed his alliance with Charles the Bald in March 857, and in the same year he dismissed Teutberga. Around the early summer of 858, with the agreement of the clergy and the nobility, Lothair subjected Teutberga to a trial by ordeal. She was allowed to pick a champion whose mission it was to pick an object out of boiling water, after which his hand would then be bandaged. A few days later the bandages were removed and the hand was deemed "uncooked," that is healing normally, and Teutberga was found not guilty. As a result, Lothair was forced by his magnates to take her back, "but he does not admit her to his bed and treats her as a prisoner."
Lothair's visit to West Francia in August, where he assisted Charles in besieging a group of Northmen, may have been partly to shore up support after the humiliation. Around that same time, Louis the German suddenly invaded West Francia, encouraged by West Francian opponents of Charles the Bald. Charles was caught unawares and forced to flee, and, at Attigny, Louis issued a charter dated to the first year of his in West Francia rule on 7 December. Lothair hurried to the palace and recognized Louis as king, but without the support of the West Frankish bishops, led by Archbishop Hincmar of Reims, Louis was forced to return to East Francia. Just as quickly, Lothair renewed his alliance with Charles. Taking advantage of their need for his support, Lothair became a mediator between his uncles. In doing so, he helped facilitate an equal peace between them at Koblenz in June 860.
Without the support of the powerful Hucbert, Lothair appealed to the family of his mother, Ermengarde of Tours, whose brother Liutfrid, as an Etichonid, held lands in Alsace and Italy. Liutfrid's position near the centre of power was compromised by Lothair's marriage to Teutberga, and the king could count on his support in ending their marriage. There was also a noble named Walther (or Walter), who was a trusted councillor of Lothair. Close clerical supporters of Lothair included Adventius, Bishop of Metz and Gunther, Archbishop of Cologne. Hucbert revolted during this time, and in 859, Lothair granted Hucbert's territories to Louis of Italy in exchange for his support. Louis gave the territory to his cousin, Conrad, who in 864 finally killed Hucbert.