The Church of the latter hale of the first millennium was practically separate because of the language if not by theology, so many of the inovations, and even father were not known.
From about 450 AD almost no one spoke Greek in the West and certainly the same was true in the East for Latin. For example, St. Photius didn't understand Latin. A bad translation of the Greek word "ecumnical" as "universal" instead of "imperial" caused serious strain in the West when the Bishop of Constantinople (Ecumenical Capital, meaning Imperial Capital) was given a title of "Ecumenical Patriarch."
St. Augustine remained virtually unknown in the East until the 15th century simply because no one could read him, etc.
But the Church was united in theology. Your Church added dogmas which we do not accept. Dogma is an obligation -- and the dogmas added especially in the last 200 years or so were more conducive to widening our split than narrowing it. The dogma of Immaculate Conception and papal Infallibility is what I am talking about, in addition to the insertion of Filioque centuries prior.
Until such dogmatic teachings are reconciled, we are not the same faith, because you must believe that which we don't.
As to the claims of papal authority, in 519 two hundred eastern bishops signed the Formula of Pope St. Hormisdas, which reads in part:
The first condition of salvation is to keep the norm of the true faith and in no way to deviate from the established doctrine of the Fathers. For it is impossible that the words of our Lord Jesus Christ, who said, "Thou art Peter, and upon this rock I will build my Church," [Matthew 16:18], should not be verified. And their truth has been proved by the course of history, for in the Apostolic See the Catholic religion has always been kept unsullied. From this hope and faith we by no means desire to be separated and, following the doctrine of the Fathers, we declare anathema all heresies, and, especially, the heretic Nestorius, former bishop of Constantinople, who was condemned by the Council of Ephesus, by Blessed Celestine, bishop of Rome, and by the venerable Cyril, bishop of Alexandria...Following, as we have said before, the Apostolic See in all things and proclaiming all its decisions, we endorse and approve all the letters which Pope St Leo wrote concerning the Christian religion. And so I hope I may deserve to be associated with you in the one communion which the Apostolic See proclaims, in which the whole, true, and perfect security of the Christian religion resides. I promise that from now on those who are separated from the communion of the Catholic Church, that is, who are not in agreement with the Apostolic See, will not have their names read during the sacred mysteries. But if I attempt even the least deviation from my profession, I admit that, according to my own declaration, I am an accomplice to those whom I have condemned. I have signed this, my profession, with my own hand, and I have directed it to you, Hormisdas, the holy and venerable pope of Rome.
Thus the claims of the Holy See were known and accepted for at least five hundred years before the Schism.
Your Church added dogmas which we do not accept. Dogma is an obligation -- and the dogmas added especially in the last 200 years or so were more conducive to widening our split than narrowing it. The dogma of Immaculate Conception and papal Infallibility is what I am talking about, in addition to the insertion of Filioque centuries prior.
As shown above, papal infallibility was taught for centuries. As to the doctrine of the Immaculate Conception, is your objection to the teaching itself or only that it has been declared infallible by Rome?