Prince-Bishopric of Liège
The Prince-Bishopric of Liège or Principality of Liège was a Roman Catholic ecclesiastical principality of the Holy Roman Empire that was situated for the most part in present-day Belgium. It was an Imperial Estate, so the bishop of Liège, as its prince, had a seat and a vote in the Imperial Diet.
Source: Wikipedia — Prince-Bishopric of Liège (CC BY-SA 4.0)