The religious controversy triggered by the Reformation posed problems for the inseparability of politics, religion and law that had always existed. Because the Reformation called into question previously recognized theological authorities and truths, rule and political action had to be theologically justified in a new or different way. The Bundestags of the Schmalkaldic League therefore became an extremely important platform for political discussion in a time of political reorientation. On the one hand, this applies to an external perspective, in which the importance of the Bundestag as an opportunity to initiate or carry out nationwide, sometimes even European, negotiation processes and strategic discussions requires analysis. On the other hand, the federal parliaments as places of strategic discussions between the members of the federal government must be examined from an internal perspective.