Lotharingia was a region in northwest Europe, comprising the Low Countries, the western Rhineland, the lands today on the border between France and Germany, and what is now western Switzerland. It was born of the tripartite division in 855, of the kingdom of Middle Francia, itself formed of the threefold division of the Carolingian Empire by the Treaty of Verdun in 843. Neither Lotharingia nor Middle Francia had any natural coherence, but each was conceived as a territorial division of a larger realm. In 870 Lotharingia, after a brief interregnum, was divided by the Treaty of Meerssen between its neighbours, East Francia and West Francia. After brief wars in 876 and 879 West Francia ceded its half of Lotharingia to East Francia by the Treaty of Ribemont (880). The Lotharingian aristocracy, in attempting to assert its right to elect a sovereign, joined the other East Frankish lands in deposing their king, Charles the Fat, in 887. Under a series of dukes that began under the child king Louis IV in 903, the Lotharingians frequently swapped allegiance between the East and West Frankish kings. In 939 the East Frankish king Otto I brought the reigning duke Gilbert to heel and incorporated Lotharingia into his realm as one of the "younger" stem duchies, whose dukes had a vote in royal elections. While the other stem duchies were tribal or national identities, Lotharingia's identity was solely political.
In 959 the Lotharingian duke Bruno the Great divided the duchy between Lotharingia superior (Upper Lorraine) and Lotharingia inferior (Lower Lorraine), giving each to the rule of a margrave. Except for one brief period (1033–44, under Gothelo I), the division was never reversed and the margraves had soon raised their separate fiefs into dukedoms. In the twelfth century the ducal authority in Lower Lorraine became fragmented, causing the formation of the Duchy of Limburg and the Duchy of Brabant, whose rulers retained the title Duke of Lothier (derived from "Lotharingia"). With the disappearance of a "lower" Lorraine, the duchy of Upper Lorraine became the primary referent for "Lorraine" within the Holy Roman Empire. After centuries of French invasions and occupations, Lorraine was finally ceded to France at the close of the War of the Polish Succession (1737). In 1766 the duchy was inherited by the French crown and became the province of Lorraine. In 1871, after the Franco-Prussian War, the German-speaking part of Lorraine was merged with Alsace to become the province of Alsace-Lorraine in the German Empire. Today the greater part of the French side of the Franco-German border belongs to the Lorraine région.
Middle Francia 
The ground for the formation of Middle Francia was laid in 817, with the plans drawn up for a division of the Carolingian Empire on the death of the emperor Louis the Pious. Unforeseen in 817 was a further claimant besides Louis's three grown sons. A fourth son, Charles the Bald, was born to Louis's second wife, Judith of Bavaria, in 823. When Louis tried in 833 to re-divide the empire for the benefit of Charles he met with the opposition of his adult sons, Lothair, Pepin, and Louis. A decade of civil war and fluctuating alliances, punctuated by brief periods of peace, followed. Pepin died in 838, and the elder Louis in 840. The remaining brothers made peace in 843 and mapped out a final division of the Empire. Lothair, as the eldest, was allowed the imperial title and received as his share of the land a long strip of territories between his brother's kingdoms, stretching from the North Sea to the Duchy of Benevento. The logic of the division was that Lothair had the allegiance of Italy, which had been his sub-kingdom under Louis the Pious, and that, as emperor, he should rule in Aachen, the capital of the first Carolingian emperor, Charlemagne, and in Rome, the ancient capital of emperors. Middle Francia (Latin Francia media) thus included all the land between Aachen and Rome and it has sometimes been called by historians the "Lotharingian axis".
Kingdom of Lotharingia 
In 855, when Lothair was on his deathbed at Prüm Abbey, he divided his kingdom between his three sons in the Treaty of Prüm. To the eldest, Louis II, went Italy, with the imperial title. To the youngest, Charles, still a minor, went Provence. To the second eldest and namesake of his father, Lothair II, went the remaining territories to the north of Provence, a kingdom which lacked ethnic or linguistic unity as much as Middle Francia as a whole had. Because of this lack of identity contemporaries were unsure what to call the kingdom and so it became regnum quondam Lotharii or Lotharii regnum ("kingdom [once] Lothair's") and its inhabitants Lotharii (from Lotharius), Lotharienses (from Lothariensis), or Lotharingi (which gives the modern German Lothringen, which is the name of the province). The latter term, formed with the Germanic suffix -ing, indicating ancestral or familial relationships, gave rise to the Latin term Lotharingia (from the Latin suffix -ia, indicating a country) in the tenth century. Later terms like "Lorraine" and "Lothier" are derived from this Latin term.
When Lothair II died in 869 he left no legitimate children, but one illegitimate son, Hugh. The kings of East and West Francia, Louis the German and Charles the Bald, agreed to divided Lotharingia between them, and in 870 they came to an agreement at Meerssen. The western half of Lotharingia went to West Francia and the eastern half to East Francia. In 876 Charles invaded eastern Lotharingia but was defeated near Andernach by Louis. In 879 Louis's son, Louis the Younger, was invited by a faction of the West Frankish nobility to succeed Louis the Stammerer, Charles's son, on the throne. In response, Louis the Stammerer's sons, Carloman II and Louis III, ceded western Lotharingia to Louis. The border between the two kingdoms was established at Saint-Quentin the next year (880).
When in November 887 Arnulf of Carinthia called a council of the East Frankish nobility to depose Charles the Fat, who had succeeded to all the kingdoms of the Empire by 884, the Lotharingians were one of those who joined him. They elected Arnulf their king, possibly under coercion. Arnful was initially opposed by Guy III of Spoleto, who eventually made himself king in Italy, and by Rudolph of Auxerre, who had been elected king in the south of Lotharingia, in Transjurane Burgundy. Rudolph intended to make himself king over the whole of Lothair II's kingdom, but he had to content himself with a rump state. In 895 Arnulf appointed his illegitimate son Zwentibold King of Lotharingia. He ruled independently until he was overthrown and killed by a rebellious magnate in 900.
Duchy of Lotharingia 
The greater freedom allowed the Lotharingian magnates by the minority of Louis IV, Arnulf's legitimate son and heir in East Francia, kept them faithful to him until his death in 911. It is during his reign that a duke first appears in Lotharingia as an intermediary between the people and the king. The first duke was Gebhard (903). His title, recorded in contemporary Latin, was dux regni quod a multis Hlotharii dicitur: "duke of the kingdom that many call Lothair's". He was succeeded by Reginar, who led the nobility in electing Charles the Simple of West Francia king after the death of Louis IV. In 915 Charles rewarded him by granting him the title margrave. Reginar was succeeded by his son, Gilbert, who used the title dux Lotharingiae: "duke of Lotharingia". When the West Franks deposed Charles in 922, he remained king in Lotharingia, whence he endeavoured to reconquer his other kingdom in 923. He was captured and imprisoned, where he died in 929. The Lotharingians did not elect a replacement until 925, when under Gilbert's leadership they chose Henry the Fowler, the East Frankish king. In 930 Gilbert's decision was rewarded and he received the prestigious hand of Henry's daughter Geberga in marriage. On Henry's death in 936 Gilbert tried to swap Lotharingian allegiance to the West Franks, since their king, Rudolph, was weak and would interfere less in aristocratic matters. In 939 Henry's son and successor, Otto I, invaded Lotharingia and defeated Gilbert in the Battle of Andernach. The dukes of Lotharingia were thereafter royal appointees.
See also 
Primary sources 
Secondary sources 
- Bartholomew, John,and Wakelyn Nightingale. Monasteries and Patrons in the Gorze Reform: Lotharingia C.850-1000 (2001)
- Clark, Samuel. State and Status: The Rise of the State and Aristocratic Power in Western Europe (1995) pp 53-79 excerpt
- Timothy Reuter, ed. The New Cambridge Medieval History, III: c. 900–c. 1024, Cambridge: Cambridge University Press, 2005. excerpts