The significance of the Edict of Milan in 313 AD was its provision of religious tolerance for Christians within the Roman Empire. Issued by Emperor Constantine, it marked a turning point in Christian history, effectively legalizing the faith after centuries of persecution. The edict allowed Christians to practice their religion openly and restored properties taken from them during previous persecutions. This shift not only facilitated the spread of Christianity but also signaled the beginning of a broader acceptance of diverse religions within the empire, paving the way for Christianity's eventual establishment as the state religion.