See that you all follow the Bishop as Christ does the Father, and the presbyterium as you would the apostles; and reverence the deacons, as a command of God. Let no one do anything connected with the Church without the Bishop. Let that be considered a certain valid eucharist which is under the leadership of the Bishop, or one to whom he has entrusted it. Wherever the Bishop appears, there let the multitude of the people be; just as where Christ Jesus is, there is the catholic church. It is not permitted without the Bishop either to baptize or to celebrate an agape; but whatever he shall approve of, that is well-pleasing also to God, so that everything that is done may be assured and certain.
St Ignatius of Antioch c.111 AD, Letter to the Smyrneans 8