There was no such thing as a “supreme pontificate” in the undivided church and St Peter was not a pope–he was an apostle.
No.
Sts Peter and Paul founded the Church in Rome. St Peter founded the Church in Antioch.
There was no such thing as a pontificate of universal jurisdiction in the undivided church. That is a later innovation.
“But since it would take too long to set out here the successions of all the Churches, we shall turn to the great, ancient and universally known Church founded and organized in Rome by the two most glorious Apostles Peter and Paul, and we shall show that the tradition it has received of the Apostles and the faith that it preaches to men has come down to our time through the regular succession of its bishops; and thus we shall confute all those who, in whatever way, whether by self-complacency, vainglory, blindness or error, enter into unauthorized assemblies. For it is with this Roman Church, by reason of its more powerful pre-eminence, that every other Church, that is to say all the faithful everywhere, ought to agree, inasmuch as the apostolic tradition has been preserved by these faithful.” (St. Irenaeus - “Contra Haereses”)
Schism and heresy were to be installed in the Churches of Antioch, Constantinople, and Alexandria, in Africa and so on. Then came the great schism between East and West. It then became apparent that the divine hierarchy could be torn in two in certain regions. It remianed whole and undivided no doubt in the true Church. But in the Church that fell away into schism only a portion of it survived. There the jurisdictional or pastoral power was interrupted; but the power of order, nevertheless, could be validly perpetuated.
Thus the proof from the apostolic succession could have two distinct applications; one when these words “apostolic succession” are given a new and more restricted sense, and one when they are taken in the more comprehensive sense we already know.
In the first case the argument from apostolicity will indicate, with an exactitude that might be called material, the presence or absence of the power of order and of the Christian in a Church. Wherever its transmission has been unbroken, there the power of order continues to exist and the cultus is validly celebrated. Apostolicity, to that extent, is safeguarded. But it is a partial and mutilated apostolicity, since apostolicity of jurisdiction is missing. Moreover this partial apostolicity is constantly threatened, for belief in the sacraments and in the Eucharist, being no longer protected against new attacks by the infallible magisterium of the Sovereign Pontiff, is liable to weaken and to drag down the power of order in its own ruin.
As a sign of the always possible disintegration of the traditional belief in the Orthodox Churches, we may recall that belief in the Immaculate Conception of Our Lady was peacefully preserved in the Greek Church till near the end of the fifteenth century, and that it disappeared from the sixteenth century onwards, partly, though undeniably, through the influence of Protestantism. Similarly, the “deuterocanonical” books of the Old Testament were received as inspired after Photius up to the eighteenth century; from then on they were openly rejected by the Russian Church, and then by numerous Greek theologians. That is the natural tendency outside the Catholic Church.
continued