Pomerania had repeatedly been Polish or independent before joining the Holy Roman Empire in 1180. Gniezno and Magdeburg archdioceses competed for expanding their influence into Pomerania, which is why the Holy See determined Cammin to remain exempt.
Pomerania's history prior to its inclusion within the Holy Roman Empire is marked by Polish or independent rule.  The Archdioceses of Gniezno and Magdeburg sought to expand their influence in Pomerania, prompting the Holy See to exempt Cammin from any restrictions.