The Polish Inquisition was an ecclesiastical institution established in the 13th century to combat heretics. Permanent structures of the inquisition in Polish territories were established in the first half of the 14th century and always played a subordinate role to episcopal tribunals, which were already combating heretics in Poland in the mid-13th century. The final end of the existence of inquisitorial tribunals came with the Reformation and the victory of the idea of religious tolerance in Poland in the second half of the 16th century.
Geographically, the jurisdiction of Polish inquisitors included territories within the Gniezno metropolitan province (including Silesia, and from the late 14th century also Lithuania) and Prussia, but did not include (except for a brief period in the 1460s) Western Pomerania, which, according to the bull of Boniface IX from 1399, was under the jurisdiction of inquisitors from the German province of Saxony. Meanwhile, Red Ruthenia, although it belonged to the Polish state from 1340 (with a brief interruption during the reign of Louis I of Hungary), until the mid-15th century formed a separate unit within the territorial structures of the papal inquisition.