I found Canon 6 of the Council of Nicea very interesting. It seems to disprove Roman Catholic notions that the Bishop of Rome is the "universal bishop" of the entire Christian Church:
Let the ancient customs in Egypt, Libya and Pentapolis prevail, that the Bishop of Alexandria have jurisdiction in all these, since the like is customary for the Bishop of Rome also. Likewise in Antioch and the other provinces, let the Churches retain their privileges. And this is to be universally understood, that if any one be made bishop without the consent of the Metropolitan, the great Synod has declared that such a man ought not to be a bishop. If, however, two or three bishops shall from natural love of contradiction, oppose the common suffrage of the rest, it being reasonable and in accordance with the ecclesiastical law, then let the choice of the majority prevail.
It shows the authority of the Bishop of Alexandria, and then goes on to say that the Bishop of Rome has a similar jurisdiction.
What are your thoughts on this?