Question

(what groups) were fighting each other in actual battles during the reformation

Answer 1

During the Reformation (in the 16th century) there were two principal groups fighting each other, Christians and Muslims. There was a huge religious war between Christianity and Islamism in central and southern Europe. Furthermore, in the same central but northwestern Europe, a separation of ideas started with Protestantism, which had different points of view in terms of religious matters that contrasted the ideas of Catholicism. Both conflicts caused many deaths and massacres in the name of God.