Roman emperors Arcadius and Honorius issue an edict restating earlier restrictions on Christian heretics. This edict brings the power of the state in defense of Christian orthodoxy, helping ensure that the mainstream, orthodox Christian churches are able to maintain an upper hand against dissident movements.
The new Roman law states:
"None of the heretics, who are now restrained by innumerable laws of Our sainted father, shall dare to assemble unlawful gathering and to contaminate with profane mind the mystery of Almighty God, either publicly or privately, secretly or openly.
None shall dare to appropriate the title bishop or, with polluted mind, to arrogate to himself the ecclesiastical order and their most sacred titles." [CTh 16.5.26]