Lorraine, as its name indicates, was in the 9th cent. part of the kingdom of Lotharingia; it became a duchy under the Holy Roman Empire. It passed in 1048 to the house of Alsace, which then became the house of Lorraine and controlled the duchy until 1738. Several fiefs emerged in the 12th–13th cent. that escaped the control of the dukes. Chief of these were the county of Barrois, later the duchy of Bar (see Bar-le-Duc), and the three bishoprics of Metz, Toul, and Verdun. Bar and Lorraine were reunited when Lorraine passed by marriage to René of Anjou, duke of Bar; the three bishoprics were finally annexed by France in 1552. René II of Lorraine helped (1477) to defeat, at Nancy, Charles the Bold of Burgundy, who had seized most of the duchy.
In the 16th cent. a cadet branch of the house of Lorraine, the Guise family, gained tremendous influence in France, while Lorraine itself, under Duke Charles II (1559–1608), enjoyed a period of relative order and prosperity amid a Europe torn by religious and imperialistic strife. Lorraine was occupied by France in the Thirty Years War (1618–48). Duke Charles IV spent most of his life trying to recover his lands, and his successor, Charles V, although he helped to recover Hungary from Turkey, never managed to recover Lorraine. At last, in the Treaty of Ryswick (1697), Leopold I was recognized in possession of the duchy.
Leopold's heir, Francis III, married Maria Theresa of Austria, became emperor as Francis I, and founded the house of Hapsburg-Lorraine. By an arrangement (1735) with Louis XV, he exchanged the duchies of Lorraine and Bar for Tuscany; Lorraine and Bar were given to Louis XV's father-in-law, Stanislaus I, ex-king of Poland, upon whose death (1766) they passed to France. As a French province, Lorraine continued to enjoy certain exemptions and privileges.
In 1871, as a result of the Franco-Prussian War, the eastern part of Lorraine was ceded to Germany and united with Alsace as the imperial land (Reichsland) of Alsace-Lorraine. Those parts of Lorraine remaining French were organized into the present department of Meurthe-et-Moselle. After World War I, Alsace-Lorraine was returned to France, but it was again annexed (1940–44) by Germany during World War II. (The unique problems of Alsace-Lorraine are discussed in the article Alsace.) During both world wars Lorraine suffered heavily.