Complex sentence: The witch-hunts would expand into Baden following it's reconquest by Tilly and the defeat of Protestantism in the Palatinate opened the way for their eventual spread to the Rhineland.
Split into simpler sentences: The witch-hunts would expand into Baden following it's reconquest by Tilly. Similarly, the defeat of Protestantism in the Palatinate campaign opened the way for the spread of the trials to the Rhineland.