Kammin, or Cammin (mod. Kamien Pomorski, Poland), was a missionary bishopric in Pomerania in the time of the crusades.
The castle and town of Kammin, situated on the river Diernow (Dziwna) facing the island of Wolin, was first mentioned in 1107 as the seat of the Pomeranian prince Wartis- law I. After conquering Pomerania, the Polish duke Boleslaw III in 1124 invited Bishop Otto of Bamberg to Christianize the Pomeranians. Churches were established in major centers such as Stettin (mod. Szczecin, Poland), Wolin, and Kam- min, and the Pomeranian bishopric, originally established at Wolin around 1140, was transferred to Kammin in 1175/ 1176. When the neighboring archdioceses of Gniezno and Magdeburg attempted to incorporate Kammin, Bishop Sigfrid in 1188 was able to get Pope Clement III to confirm an earlier exemption and place Kammin under direct papal protection.
Nevertheless, the Danes acquired considerable influence in the diocese. Following a Danish crusade against Stettin around 1173, a Cistercian monastery was founded in Kolbatz from Esrom in Denmark and a Premonstratensian monastery, Belbuck, from Lund. In the 1180s another Premon- stratensian house in the diocese, Grobe, was affiliated with Tommarp in the Danish archdiocese of Lund. In 1185 King Knud VI of Denmark even directed a crusade against Kam- min itself. Although the clergy went out in procession, imploring the king not to commit sacrilege, only the timely submission of Duke Bogislaw I of Pomerania saved the town. During the next forty years Kammin played an important role in furthering the Danish crusades to Prussia, particularly with the appointment of a Cistercian from Kolbatz, Christian, as bishop of Prussia.
After the collapse of Danish power in the Baltic region in 1223-1227, the Pomeranian dukes once more took control, and Kammin lost its importance in the crusading movement.