In 673, at the instance of Theodore, and under the presidency of Hlothere, King of Kent, a synod was held at Hertford, attended by all the English bishops but one, and by the kings and many of the principal nobles and clergy, at which the independent national Churches agreed to unite in an Ecclesiastical Province, with the Bishop of Canterbury as its metropolitan; it was further agreed that the bishops and clergy should meet in synod twice a year, once always in August at Clovesho, the other was probably left to the convenience of the moment as to time and place, but was usually held at Cealchyth. Augustine and his successors at Canterbury had never been practically more than bishops of the Kentish men, with the titular distinction of archbishop which Gregory gave them. Theodore, says Bede, was the first archbishop whom the Churches of the English obeyed. This gave Theodore the authority necessary for the carrying out of his plans for the peace and progress of the Church.
One feature of Theodore's policy was the breaking up of some of the larger sees. This was not done without opposition. There was much to be said in favour of the idea of "one king one bishop;" it fell in with the political organization and it had the prestige of ancient use. But Theodore, looking at the subject from his point of view, as the ruler of an ecclesiastical province, saw the desirableness of breaking it up into dioceses of more manageable size. He was opposed by Wilfrid of York, who resented the diminution of his great position as Bishop of the Northumbrian kingdom, by the division of the diocese into four, York, Lindisfarne, Hexham, and Whithern; but his opposition was overborne by the firmness of the King of Northumbria and the archbishop. Wilfrid carried his complaint to Rome, which is the first example of an appeal from the English to the Roman Court, and raises the question of the relations of the English Church to the Bishop of Rome. It is sufficient to say here in reference to the Roman decision in Wilfrid's favour on this and subsequent occasions, that neither Archbishop Theodore, nor the clergy, nor the king and thanes of the Witan, showed any disposition to accept the intervention of the Bishop of Rome, or to defer to his judgment in the matter; and that Wilfrid was punished by the king with imprisonment and exile for his contumacy.