This chapter offers a novel account of the rise of religious freedom. Religious and political power have been bound together since prehistory. As a consequence, there was an absence of religious freedom throughout most of history. Even when religious dissidents were not being persecuted for their beliefs, religious practice was not free. We investigate the motivations that led some states to persecute individuals for their religious beliefs and other states to abstain from persecution. We argue that the rise of modern states—states capable of enforcing general rules and the rule of law—made possible religious peace and the eventual rise of religious and other liberal freedoms.