This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
In 297 CE the Roman emperor Diocletian ordered Manichaeism annihilated within the empire's borders, treating it as a subversive Persian sect at a moment of open war between Rome and Persia, a charge of foreign loyalty layered on top of the same accusation of heresy that had already ended Mani's own life at home two decades earlier.
The edict's terms were severe. Manichaean leaders and their sacred books were to be burned, and ordinary believers faced execution or forced labor in the mines, a punishment scaled to treat the faith as both a religious threat and a matter of state security rather than as an ordinary case of unwelcome preaching.
The order did not extinguish the faith outright. Manichaeism, which had already survived the execution of its own founder in Persia a generation earlier, went underground across the territories its missionaries had spread into rather than disappearing, and Christian emperors who came after Diocletian renewed similar bans against it through the fourth and fifth centuries, treating it as a continuing threat long after its formal proscription under a still pagan Rome.
What Diocletian's order changed for Manichaeism's spread in the Roman world was the end of open practice. A faith that had crossed from Egypt to Italy within a generation of its missionaries' arrival was driven back underground by imperial decree, and stayed there under successive Christian emperors for two centuries more, surviving as a hidden movement rather than the open rival to Roman religion it had briefly become.