Constantine really had only an indirect role in shaping Christianity as a religion. He called the council of Nicea, but didn't determine anything of its outcome. If anything, he seems to have been more concerned with internal peace within the empire, than with the actual veracity of the Arian position, and Arianism and Semi-Arianism continued for centuries after him.
On this we agree. And we might agree on your entire post. By the way the major reason Arianism continued after St. Constantine is because the sinister Eusebius of Nicomedia, who may have been aided by a goodwill push by Eusebius of Caesarea, who sympathized with the Arians and famously equivocated at Nicaea, saying “I sign with my hand but not my heart”, worked to restore Arius to imperial favor and orchestrate the exile of St. Athanasius the Great. Indeed it was Eusebius of Nicomedia who baptized St. Constantine on his deathbed. Thus his son Constantius became an Arian and a major persecutor of Christians, and severe persecution continued until Julian the Apostate, who stopped persecuting Christians in favor of Arians, and released St. Athanasius from exile because he perceived this would annoy the majority of Christians due to the pervasiveness of Arianism at this time. It did not, and the return of St. Athanasius from Germany to Egypt was a cause for public celebration. Valens also was less severe, but the persecution didn’t end until the reign of Emperor St. Theodosius, and even he intended to hand over a basilica in Milan to the Arians in order to keep the peace, which prompted St. Ambrose to organize a vigil in that basillica at which time he introduced Eastern Christian antiphonal singing of the form that originated in Antioch under St. Ignatius the Martyr, to keep the spirits of his people up, “lest they perish in soulless monotony.” This is recognized as the origin of the Ambrosian Rite, and quite possibly of the distinctive Gallican Rite, unless the Gallican chant already existed in Gaul, Spain and Southern Italy (it began to be suppressed under Charlemagne, starting in Gaul, in favor of the Roman Rite), and was already incorporating Eastern-style antiphony, which is quite possible, given the extreme conservatism of the ancient Roman church, which took over a century to introduce a Latin liturgy and the Vetus Latina despite Latin being the majority language, and even in the case of the Vulgate rejected St. Jerome’s translation of the Psalter directly from the Hebrew, insisting he translate from the Septuagint.
At the time, the extremely conservative Roman church chanted in monotone, and indeed even after the introduction of the Ambrosian hymns and Gregorian Chant, which was an adaptation of early Byzantine Chant and uses the same eight tone system as Ambrosian, Byzantine and West Syriac Chant (and I believe Armenian Chant, but don’t quote me on that), as well as the newer Slavonic Chants, Low Masses in the Roman Rite continued to be chanted in monotone until the tenth century, by which time priests adopted the custom of praying them silently or in a low voice or whisper audible only to the altar server (except in some cases where the Scripture is read aloud, at present). There was also in the early 20th century the Dialogue Mass, and since at least the 18th century the Missa Cantata, the latter of which allowed the celebration of the mass with music without having a deacon and subdeacon as required by a Solemn High Mass or a Solemn Pontifical Mass (although there are also Pontifical Low Masses, one famous example of which was the Pontifical Requiem for President John F. Kennedy, which was said as a pontifical low requiem mass I believe due to the wishes of the bereaved Jacqueline Kennedy, later to be wed to Aristotle Onassis, as you doubtless know but which I mention for the benefit of teenaged members of the forum who might read this thread and be unaware of that historical fact, although, I must confess, I admit the prospect of a teenager having the desire to read one of my verbose posts is limited, if not entirely absent (I do actually relate well to intelligent teenagers in person and I think one of my strengths as a clergyman is my skill at youth ministry; I have been actively encouraged to launch a YouTube channel by some and am considering it).
At any rate, this conservativism, on the part of the Roman Church, which lasted in my opinion until Leo I, who was the first to style himself “Pontifex Maximus” and who was also the first to intervene with his own personal views in an ecumenical council, an event which lead to the EO/OO schism which sadly continues until the present, so I myself am not a fan of Leo I. However I love St. Celestine, who did everything in his power to support St. Cyril the Great in his struggle against Nestorius (and indeed Patriarch John of Antioch, whose interference in the move to depose and anathematize Nestorius is well known.
What I found striking in my own research was the number of fathers who were disappointed in the outcome of Nicea, because the whole affair was quite quarrelsome and the council really settled very little in the short term. As a result, some basically swore off church politics after that.
The main reason why Nicea was less than entirely effective was because of the efforts of the more subtle heretics to exploit an oversight in the original version of the Nicene Creed, for example, its lack of specificity regarding the nature of the Holy Spirit, which enabled the Pneumatomacchians.
The revised creed adopted at the Council of Constantinople in 381, which is the Second Ecumenical Council and which like the Council of Nicaea, is recognized by all normative Christian churches including the Assyrian Church of the East and the Ancient Church of the East, and was even during the period when they adhered to a Nestorian Christology, before adopting the quasi-Chalcedonian Christology of Mar Babai the Great in the early sixth century, with the Oriental Orthodox accepting the first three, and also the basic principles of the fifth, sixth and seventh (insofar as they reject mongergism, monothelitism and iconoclasm; indeed the Oriental Orthodox never had a Patriarchate fall under the control of Iconoclasts, and the only outbreak of iconoclasm in the Oriental church was a brief outbreak in the Armenian Apostolic Church which was quickly suppressed).
The Oriental Orthodox (specifically, St. Severus of Antioch) also gave us the hymn Ho Monogenes, which was adopted by the Eastern Orthodox under Emperor Justinian* I and by the Catholics via the sui juris Eastern Catholic Churches as the surest guarantee of Christological Orthodoxy, in that if you can sing it your Christology is Orthodox.
Only-Begotten Son and Immortal Word of God,
Who for our salvation didst will to be incarnate of the holy Theotokos and Ever-Virgin Mary;
Who without change didst become man and was crucified;
Who art one of the Holy Trinity, glorified with the Father and the Holy Spirit:
O Christ our God, trampling down death by death, save us!
*Justinian is sometimes credited with writing the hymn, but this is obviously a pious misattribution by Eastern Orthodox unwilling to concede an important part of their liturgy was of Oriental Orthodox origin. We can say this attribution is false because the hymn opens every Syriac Orthodox Qurbono Qadisho (Divine Liturgy, or literally, Holy Sacrifice), occupying a more prominent position in the Qurbono than the hymn occupies in the Byzantine Rite Liturgy of the Catechumens, or Synaxis, (indeed, if memory serves the hymn is not even heard in current Byzantine recensions of the Divine Liturgy and Presanctified Liturgy of St. James, which are used infrequently, but it is also not heard in the Vesperal Divine Liturgy of St. Basil, which is used on several occasions throughout the year, but it is used during regular celebrations of the Divine Liturgy of St. Basil on Saturdays and Sundays of Great Lent (unless the Feast of the Annunciation falls on a Sunday, or indeed any day - it is always celebrated using the Divine Liturgy of St. John Chrysostom). Ho Monogenes is also not heard in the Presanctified Liturgy of St. Gregory, which is used on weekdays in Great Lent and on Monday, Tuesday and Wednesday of Holy Week. The current appearance of the hymn in the Armenian Soorp Badarak (Holy Sacrifice, or divine liturgy) is also in the Synaxis, or Liturgy of the Catechumens, which was adopted from the Byzantine Rite during a period of close relations with the Eastern Orthodox probably during the military alliance of Armenia and the Armenian Kingdom of Cilicia with the Byzantine Empire (there was also a period of Latin influence, which you can see in the shape of Armenian mitres, the use of the organ and the recitation of John 1:1-14 at the end of the Badarak; in the Tridentine Mass this is called “the Last Gospel” as it is read at the end of every Solemn High Mass, a tradition I particularly love, as I regard John 1 to be extremely important).
It literally makes no sense that the Syriac Orthodox would adopt a hymn to open their liturgy with, which along with the Trisagion is one of the two most high profile hymns in the entire Qurbono, when they were persecuted viciously by the same Emperor Justinian who allegedly wrote it, after his attempts to reunite them with the Eastern Orthodox failed, with all of their bishops except St. Jacob Baraddaeus being killed off; St. Jacob (who survived probably because of advance warning he received from St. Theodora, the Syriac Orthodox Empress Consort of Justinian) then ordained a very large number of bishops acting sola, which is generally considered acceptable only in emergencies, since normally you need three bishops to ordain another bishop, in the Eastern churches at least. This is why for many years the Syriac Orthodox were called Jacobites (not to be confused with supporters of Bonnie Prince Charlie and a Stuart restoration to the Scottish and English thrones, also called Jacobites because of the deposed King James II) and those loyal to the Patriarch of Antioch in the rather nasty schism plaguing the church in India still identify as Jacobites.
There is also a theory that the hymn was written by St. Athanasius in the first century, but this seems even less likely than his supposed authorship of Quincunque Vult, better known as the Athanasian Creed, not because there is any suggestion he would have disagreed with it (indeed, I feel confident in saying he would not have), but rather because the hymn appears written to articulate the doctrine of St. Cyril the Great in opposition to Nestorianism (and the early Oriental Orthodox Church of Antioch, both its Greek and Syriac speaking members, St. Severus being among the former, refused, like the other Oriental Orthodox churches**
**At the time these were the Coptic Orthodox Patriarchate of Alexandria and two autonomous churches under its aegis, the Numidian Orthodox Church, which was killed off by the Muslims, and the Ethiopian Tewahedo Orthodox Church, which became autocephalous during the reign of the martyred Emperor St. Haile Selassie, who was strangled by the communist Derg regime for among other things, refusing to renounce the Christian faith, and also the Armenian Apostolic Church. Since that time, the Armenian church has developed into four churches, each led by an autocephalous primate, in order of precedence, the Catholicos of Holy Etchmiadzin, the ancient cathedral in Armenia which is the oldest functioning cathedral in the world and one of the two oldest cathedral buildings, along with the Hagia Sophia in Constantinople, the Catholicos of the Great House of Cilicia, originally established when the second Armenian Kingdom, Cilicia, was founded, but presently headquartered in Lebanon, the Patriarchate of Jerusalem, who is in charge of the Armenian church in the Holy Land, which also represents the interests of the other Oriental Orthodox churches at the Basillica of the Holy Sepulchre and the Church of the Nativity (which it jointly constructed with the Greek Orthodox), being one of the three main entities in charge of these sites, the others being the Greek Orthodox Patriarchate of Jerusalem, and the Roman Catholic Church, and lastly the Armenian Patriarch of Constantinople, whose job used to be very important as the representative of all Armenians at the Sublime Porte, but since the Turkish genocide of Armenians in 1915, which Turkey not only refuses to acknowledge, but has actively supported Azeribaijani*** invasions of the Armenian territory of Ngorno-Karabash, has mainly consisted of preserving the small number of Armenians who managed not to be killed and continue living in Turkey, mainly in Istanbul.
Then, the St. Thomas Christians in India who did not submit to the Roman Catholic Church joined the Syriac Orthodox Church (they had been a part of the Church of the East, and later Assyrian missions converted a small number of them), where there has since been a schism between those loyal to the Patriarch in Antioch and the Maphrian, the bishop second in precedence in the Syriac Orthodox hierarchy, who presides over the ordination of the Patriarch, and vice versa, and those who desire indigenous rule (who have been rather unfairly supported by the Indian courts, resulting in persecutions of the Jacobites), and there is also a third group, the Malankara Independent Syrian Church, which I don’t think is in regular communion with the other Oriental Orthodox churches, but which is in full communion with the Protestant Mar Thoma Syrian Church, which was established in an unethical manner by collusion between a Calvinist-leaning bishop and the British East India Company, but which has since become a decent enough church, and which is a member of the Anglican Communion, making the Malankara Independent Syrian Church important as the only Orthodox Church in communion with a member of the Anglican Communion.
Lastly the independence of Eritrea resulted in the creation of the autocephalous Eritrean Tewahedo Orthodox Church with assistance from the Coptic Orthodox Church, which caused a brief schism with the Ethiopians which has since healed.
*** Before it was converted to Islam, probably by force, Azerbaijan was called Albania, and to add to the confusion, Georgia is also known as Iberia, and thus there existed an Albanian Church unrelated to the autocephalous Albanian Orthodox Church in the Balkans, which was probably Oriental Orthodox but possibly Eastern Orthodox. There is presently an effort to revive this church, and it has a single parish in Baku, with I think around 50 members, at most. However, I am hopeful it is successful, because the conversion of Azerbaijan to Christianity would go a long way to stabilizing the Caucasian area, which has been traumatized both by the war between Azerbaijan and Armenia, and between Georgia and Russia. Ironically, most trade to Armenia now passes through Iran.
