For the first thousand years the churches of East and West were in one communion. This timeline quotes the creed and canons they shared, then the points on which they came apart: the words "and the Son" in the Creed, the authority of the bishop of Rome, unleavened bread, purgatory, and later the Immaculate Conception and papal infallibility. The Orthodox side and the Catholic side each speak in their own words, in date order. It ends with the lifting of the excommunications in 1965 and where the question of the primacy stood in 1995.
Drafted from primary sources. Every quotation is checked against the page it links to. The translations are those of the linked pages. No approved page was found for Cardinal Humbert's bull of 1054, the writings of Photius or Mark of Ephesus, so 1054 is shown through the patriarch's own letter and through the 1965 joint declaration.
“And in the Spirit, the holy, the lordly and life-giving one, proceeding forth from the Father, co-worshipped and co-glorified with Father and Son, the one who spoke through the prophets; in one, holy, catholic and apostolic church.”
“The fathers rightly accorded prerogatives to the see of older Rome, since that is an imperial city; and moved by the same purpose the 150 most devout bishops apportioned equal prerogatives to the most holy see of new Rome, reasonably judging that the city which is honoured by the imperial power and senate and enjoying privileges equalling older imperial Rome, should also be elevated to her level in ecclesiastical affairs and take second place after her.”
“And we speak likewise of the Holy Spirit as from the Father, and call Him the Spirit of the Father. And we do not speak of the Spirit as from the Son : but yet we call Him the Spirit of the Son. … And we confess that He is manifested and imparted to us through the Son.”
“Furthermore, nobody else should compose or edit writings or tracts against the most holy pope of old Rome, on the pretext of making incriminating charges, as Photius did recently and Dioscorus a long time ago. Whoever shows such great arrogance and audacity, after the manner of Photius and Dioscorus, and makes false accusations in writing or speech against the see of Peter, the chief of the apostles, let him receive a punishment equal to theirs.”
Eastern Orthodox: parted from the Catholic Church. The legates of the pope and the patriarch of Constantinople excommunicate each other. This is the date usually given for the break between East and West.
“reasoning badly and dangerously, they have made some sort of addition to the holy creed, so that it is as follows: "...and in the Holy Spirit, the Lord, the giver of life, who proceeds from the Father and the Son."”
“We profess faithfully and devotedly that the holy Spirit proceeds eternally from the Father and the Son, not as from two principles, but as from one principle; not by two spirations, but by one single spiration. This the holy Roman church, mother and mistress of all the faithful, has till now professed, preached and taught; this she firmly holds, preaches, professes and teaches; this is the unchangeable and true belief of the orthodox fathers and doctors, Latin and Greek alike.”
“We declare that when holy doctors and fathers say that the holy Spirit proceeds from the Father through the Son, this bears the sense that thereby also the Son should be signified, according to the Greeks indeed as cause, and according to the Latins as principle of the subsistence of the holy Spirit, just like the Father. … We define also that the explanation of those words “and from the Son” was licitly and reasonably added to the creed for the sake of declaring the truth and from imminent need.”
“Also, the body of Christ is truly confected in both unleavened and leavened wheat bread, and priests should confect the body of Christ in either, that is, each priest according to the custom of his western or eastern church. Also, if truly penitent people die in the love of God before they have made satisfaction for acts and omissions by worthy fruits of repentance, their souls are cleansed after death by cleansing pains; and the suffrages of the living faithful avail them in giving relief from such pains”
“We also define that the holy apostolic see and the Roman pontiff holds the primacy over the whole world and the Roman pontiff is the successor of blessed Peter prince of the apostles, and that he is the true vicar of Christ, the head of the whole church and the father and teacher of all Christians, and to him was committed in blessed Peter the full power of tending, ruling and governing the whole church, as is contained also in the acts of ecumenical councils and in the sacred canons.”
“Wherefore the One, Holy, Catholic, and Apostolic Church, following in the steps of the holy Fathers, both Eastern and Western, proclaimed of old to our progenitors and again teaches today synodically, that the said novel doctrine of the Holy Ghost proceeding from the Father and the Son is essentially heresy, and its maintainers, whoever they be, are heretics, according to the sentence of Pope St. Damasus, and that the congregations of such are also heretical, and that all spiritual communion in worship of the orthodox sons of the Catholic Church with such is unlawful.”
“if anyone says that the Roman pontiff has merely an office of supervision and guidance, and not the full and supreme power of jurisdiction over the whole church, and this not only in matters of faith and morals, but also in those which concern the discipline and government of the church dispersed throughout the whole world; or that he has only the principal part, but not the absolute fullness, of this supreme power; or that this power of his is not ordinary and immediate both over all and each of the churches and over all and each of the pastors and faithful: let him be anathema.”
“we teach and define as a divinely revealed dogma that when the Roman pontiff speaks EX CATHEDRA, that is, when, in the exercise of his office as shepherd and teacher of all Christians, in virtue of his supreme apostolic authority, he defines a doctrine concerning faith or morals to be held by the whole church, he possesses, by the divine assistance promised to him in blessed Peter, that infallibility which the divine Redeemer willed his church to enjoy in defining doctrine concerning faith or morals.”
“But having recourse to the fathers and the Ecumenical Councils of the Church of the first nine centuries, we are fully persuaded that the Bishop of Rome was never considered as the supreme authority and infallible head of the Church, and that every bishop is head and president of his own particular Church, subject only to the synodical ordinances and decisions of the Church universal as being alone infallible, the Bishop of Rome being in no wise excepted from this rule, as Church history shows.”
“The orthodox Eastern and catholic Church of Christ, with the exception of the Son and Word of God, who was ineffably made man, knows no one infallible upon earth.”
“The one holy, catholic and apostolic Church of the seven Ecumenical Councils teaches that the supernatural incarnation of the only-begotten Son and Word of God, of the Holy Ghost and the Virgin Mary, is alone pure and immaculate; but the Papal Church scarcely forty years ago again made an innovation by laying down a novel dogma concerning the immaculate conception of the Mother of God and ever-Virgin Mary, which was unknown to the ancient Church”
“The one holy, catholic and apostolic Church of the seven Ecumenical Councils, walking according to the divinely inspired teaching of the Holy Scripture and the old apostolic tradition, prays and invokes the mercy of God for the forgiveness and rest of those 'which have fallen asleep in the Lord'; [13] but the Papal Church from the twelfth century downwards has invented and heaped together in the person of the Pope, as one singularly privileged, a multitude of innovations concerning purgatorial fire, a superabundance of the virtues of the saints, and the distribution of them to those who need them, and the like”
“They likewise regret and remove both from memory and from the midst of the Church the sentences of excommunication which followed these events, the memory of which has influenced actions up to our day and has hindered closer relations in charity; and they commit these excommunications to oblivion.”
“I am convinced that I have a particular responsibility in this regard, above all in acknowledging the ecumenical aspirations of the majority of the Christian Communities and in heeding the request made of me to find a way of exercising the primacy which, while in no way renouncing what is essential to its mission, is nonetheless open to a new situation. For a whole millennium Christians were united in "a brotherly fraternal communion of faith and sacramental life ... If disagreements in belief and discipline arose among them, the Roman See acted by common consent as moderator".”