The Prince-Bishopric of Liège was a state of the Holy Roman Empire in the Low Countries, situated for the most part in present Belgium, which was ruled by the Bishop of Liège who held an Imperial Estate and had seat and voice at the Imperial Diet. The Prince-Bishopric of Liège should not be confused with the diocese of Liège, which was larger.
The bishops of Liège acquired their status as a Prince-bishop between 980 and 985 when Bishop Notger, who had been the bishop of Liege since 972, received secular control of the County of Huy from Otto II, Holy Roman Emperor.
The Prince-Bishopric belonged from 1500 on to the Lower Rhenish–Westphalian Circle. Its territory included most of the present Belgian provinces of Liège and Limburg, and some exclaves in other parts of Belgium and the Netherlands.
It briefly became a republic (the Republic of Liège) from 1789 to 1791, before reverting to a Prince-Bishopric in 1791. The role of Prince-Bishop permanently ended when the state was annexed by France in 1795. In 1815 it became part of the United Kingdom of the Netherlands, and in 1830 it was within the part of that kingdom which split off to become Belgium.
The principality ruled by the bishops of Liège was never part of the Seventeen Provinces or the Spanish and Austrian Southern Netherlands, but from the 16th century onwards its politics were strongly influenced by the dukes of Burgundy and later the Habsburgs, though remaining under the sovereignty of the family de la Marck (Dutch: van der Marck).
In 1559 its 1,636 parishes were grouped into eight archdeaconries, and twenty-eight councils, chrétientés (deaneries). The most important cities (bonnes villes) of the bishopric were: Liège, Beringen, Bilzen, Borgloon, Bree, Châtelet, Ciney, Couvin, Dinant, Fosses-la-Ville, Hamont, Hasselt, Herk-de-Stad, Huy, Maaseik, Peer, Sint-Truiden, Stokkem, Thuin, Tongeren, Verviers, Visé and Waremme.
The city of Maastricht fell under the joint jurisdiction of the Prince-Bishop of Liège and the Duke of Brabant (later the States-General of the United Provinces). The second city of the prince-bishopric thus kept its status aparte throughout the ancien régime.