The Duchy of Limburg was a state of the Holy Roman Empire. Its main territory including the capital Limbourg is today located within the Belgian provinces of Liège, with smaller parts in the neighbouring province of Limburg (Voeren and Rekem) and the Dutch province of Limburg (southern part), as well as in the German state of North Rhine-Westphalia (Herzogenrath).
From about 1020, Limburg Castle served as the residence of the Counts of Limburg, who in 1100 adopted the ducal title (Herzog) as Dukes of Lower Lorraine. The extinction of the line in 1283 sparked the War of the Limburg Succession, whereafter Limburg was ruled by the Dukes of Brabant in personal union. After the failed Brabant Revolution in 1789, the duchy's history was terminated with the occupation by French Revolutionary troops in 1793.