The personality of Holy Emperor Constantine the Great remains more than outstanding for the entire Christianity. Since the Edict of Milan (313) and continuing with all the politics of sustaining Christianity, Constantine will stay in the memory of the Church as „the same with the Apostles”. Apostles who have never actioned in a unilateral way in any dogmatic, liturgical and canonical problems which they had debated in a Synod. Constantine the Great revealls from the catacombs a Church which had since the beginning a well-defined hierarchy. Local councils prior to the Ecumenical from 325, show the existence of synodality inside the Church. By his participating in a Synod, the Bishop in generally connects his community to the entire Church, which was achieved in ecumenical way by organizing the First Ecumenical Council of Nicaea in 325 by Holy Emperor Constantine the Great.