<Li> Wars of Kappel </Li> <Tr> <Td> Opposition (show) <Ul> <Li> Catholic Church </Li> <Li> Council of Trent </Li> <Li> Anti-Protestantism </Li> <Li> Criticism of Protestantism </Li> <Li> Charles V, Holy Roman Emperor </Li> <Li> Ferdinand II, Holy Roman Emperor </Li> </Ul> </Td> </Tr> <Ul> <Li> Catholic Church </Li> <Li> Council of Trent </Li> <Li> Anti-Protestantism </Li> <Li> Criticism of Protestantism </Li> <Li> Charles V, Holy Roman Emperor </Li> <Li> Ferdinand II, Holy Roman Emperor </Li> </Ul> <Li> Council of Trent </Li>

What was the rood cause of the thirty years' war