German state church law is a discipline in transition. The structural changes in religion (secularization, individualization, fundamentalism) do not leave the corresponding legal field untouched. The same applies to the Europeanization of our legal system. German state church law is a discipline connected to its own history, which shapes it. The author attempts to illustrate this tension in state church law between tradition and transformation using the example of public law religious communities. The focus is on a systematic presentation of the legal status that religious communities incorporated under Article 137 V of the Weimar Constitution occupy in German and European law. The result is a compendium of religious law that addresses constitutional theoretical foundations as well as other relevant aspects.