The Apostolic Canons

“The bishops of every nation must acknowledge him who is first among them and account him as their head, and do nothing of consequence without his consent; but each may do those things only which concern his own parish, and the country places which belong to it. But neither let him (who is the first) do anything without the consent of all; for so there will be unanimity, and God will be glorified through the Lord in the Holy Spirit. (Canon 34 [35], late fourth century).