The first Council of Arles was convened in 314CE. I mentioned this recently regarding Donatism, but there was more to discuss than that.
Besides declaring Donatism heresy and excommunicating Donatus Magnus, they determined that those who truly were traditors by turning their holy books over to persecutors would be deposed, but their official acts would not be declared invalid.
The Council also determined:
The date of Easter should be held on the same day throughout the Christian world, not on a day set by each individual church.
Ordaining a priest required the approval and cooperation of at least three bishops. Clergy must live in the parish they were supposed to manage.
Actors, and those who participated in gladiatorial combat and races in the arena, should be excommunicated
This was all started right after the Edict of Milan, when everything changed for the early Christian Church. We'll get to that tomorrow.