The article analyzes the main Egyptian festivals during the Greco-Roman period concerning the influence of Greek and Roman mystery religions, which significantly affected changes in Egyptian festive culture. Through the examination of Egyptian temple reliefs, including calendar lists and scenes of the Osirian Khoiak Festival, the Coronation of the Sacred Falcon, the Feast of the Beautiful Reunion, as well as lunar festivals, it becomes evident that, from the Hellenistic period onwards, gloomy mystical subjects prevailed in the programs of Egyptian festivals. The rituals were reminiscent of dramatic performances rooted in the myths of Osiris' and Dionysus-Zagreus' deaths. The festival concept strengthened the principles of dualism of ideas and things, which were seen in ancient mysteries and involved the immersion of the participants in the darkness and then their unexpected exit to the dazzling light. These actions were associated with initiation stages, symbolizing the soul's transition from the material world to the spiritual realm, and its posthumous exit from the dark depths of the underworld to Elysium, or the Isles of the Blessed, linked to the Egyptian Fields of Iaru. This dualistic festival concept is expressed, for example, in the reliefs of Dendera and Edfu temples, representing the processions of priests descending into dark rooms and ascending to the temple roof with statues of deities for the rite Xnm itn (meaning "unity with the solar disk"). At the same time, the balance between solar and lunar cults inherent to the ancient Egyptian religion was violated during the Greco-Roman period. The religious practices proposed a shift of the emphasis towards the Osirian cult, correlated with the moon phases.
