Prince-Bishopric of Warmia

The Prince-Bishopric of Warmia (Polish: Biskupie Księstwo Warmińskie; German: Fürstbistum Ermland) was a semi-independent ecclesiastical state, ruled by the incumbent ordinary of the Warmia see and comprising one third of the then diocesan area. The Warmia see was a Prussian diocese under the jurisdiction of the Archbishopric of Riga that was a protectorate of the Monastic state of the Teutonic Knights (1243–1464) and a protectorate and part of the Kingdom of Poland—later part of the Polish–Lithuanian Commonwealth (1464–1772), confirmed by the Peace of Thorn in 1466.

Source: Wikipedia — Prince-Bishopric of Warmia (CC BY-SA 4.0)