Decline of Greco-Roman polytheism

Religion in the Greco-Roman world at the time of the Constantinian shift mostly comprised three main currents:the traditional religions of ancient Greece and Rome;the official Roman imperial cult;various mystery religions, such as the Eleusinian Mysteries and the mystery cults of Cybele, Mithras, and the syncretized Isis.Early Christianity grew gradually in Rome and the Roman Empire from the 1st to 4th centuries, when it was legalized and, in its Nicene form became the state church of the Roman Empire with the Edict of Thessalonica of 380. Hellenistic polytheistic traditions survived in some pockets of Greece into the 9th century. The Neoplatonic Academy was shut down by Justinian I in 529, a date sometimes taken to mark the end of Classical Antiquity.