St. Pope John I

“Among the conspicuous reasons for praising your wisdom and gentleness, Most Christian of Emperors, and one which radiates light as a star, is the fact that through love of the Faith, and actuated by zeal for charity, you, learned in ecclesiastical discipline, have preserved reverence for the See of Rome, and have subjected all things to its authority, and have given it unity. The following precept was communicated to its founder, that is to say, the first of the Apostles, by the mouth of the Lord, namely: "Feed my lambs." [John 21:15] This See is indeed the Head of all the churches, as the rules of the Fathers and the decrees of the Emperors assert.”


“This See is indeed the head of all churches, as the rules of the Fathers and the decrees of the Emperors assert, and the words of your most reverend piety testify. It is therefore claimed that what the Scriptures state, namely, "By Me Kings reign, and the Powers dispense justice;" will be accomplished in you. For there is nothing which shines with a more brilliant lustre than genuine faith when displayed by a prince, since there is nothing which prevents destruction as true religion does, for as both of them have reference to the Author of Life and Light, they disperse darkness and prevent apostasy. Wherefore, Most Glorious of Princes, the Divine Power is implored by the prayers of all to preserve your piety in this ardor for the Faith, in this devotion of your mind, and in this zeal for true religion, without failure, during your entire existence….” (St. Pope John I to Emperor Justinian before the Council of Constantinople II, notably included in Justinian’s Law Code, which shows that he approved of the claims made here to some extent.)