When Was Our Understanding of the Adjective “Nicene” Was Invented (Spoiler: Not in 325)

 I knew nothing about any of this before this month, so let’s start with the facts as they look to me now.

Constantine favored the Arians. The Western texts complicate things (by lying). Constantine was an Arian. His son who succeeded him to greatness was an Arian. That alone should make us suspicious of the tidy story where “Nicaea = anti-Arian, forever and always.”

If the emperor and his dynasty leaned Arian, and they’re the ones actually running the empire, then it is more likely than not that the creed of Nicaea, whatever it originally meant, was perfectly compatible with Arian or homoian theology as it was actually lived in the fourth century. The later stories about Arians being “anti-Nicene” are exaggerations written after the fact.

What we now call “Nicene” orthodoxy – the thing that supposedly descends straight from 325 – looks like a Roman invention from around 380 CE, a historical revision project carried out when it suddenly became politically useful for Rome to claim it had always been the guardian of the true faith.

Here’s what I mean.

1. The road to 381: why the “Nicene” side had such a weak footing

After Nicaea (325), the East is mostly run by emperors who are at least homoian or “Arian-leaning.” That alone should puncture the fantasy that Nicaea settled everything.

Constantius II (sole ruler 353–361) is aggressively anti-Athanasius and backs homoian councils. Valens in the East (364–378) is again homoian and staffs the Eastern episcopate with his people.

The result: in the East, for decades, the imperial court and the bishop of Constantinople are on the Arian/homoian side. Rome and (much of the time) Alexandria are the awkward outliers defending some version of “Nicaea” against the reigning theology of the capital.

As long as that configuration lasts, a “Nicene tradition” centered on Rome is impossible. Doctrine is made where the emperor is, and that’s Constantinople. If the emperor and his court bishops are homoian, that’s the de facto orthodoxy, whatever creeds you can dredge up from 325.

2. The political crash: 378–381

Everything changes very fast.

Battle of Adrianople (378): Valens is killed by the Goths. The homoian regime in the East literally dies on the battlefield.

Gratian and Theodosius (from 379): Gratian in the West appoints Theodosius I as Eastern emperor. Gratian is pro-Roman see (what will soon be labeled “Nicene”) and close to Damasus of Rome and Ambrose of Milan. Theodosius quickly moves into the same orbit. Suddenly the imperial center of gravity shifts toward the Roman version of things.

Then comes the Edict of Thessalonica (380). This is the bombshell. Theodosius defines the only legitimate Christianity as the faith “which the divine Apostle Peter delivered to the Romans” and which is confessed “by the bishop of Rome and the bishop of Alexandria.”

That does two things at once:

It canonizes the Roman–Alexandrian line as the norm of orthodoxy.

It implicitly delegitimizes the homoian tradition that had dominated Constantinople under Constantius and Valens.

In other words, the emperor is now publicly saying: real Christianity is whatever the bishop of Rome (and his Alexandrian friend) say it is. That is not Nicaea 325. That is Rome 380.

Then the Council of Constantinople (381) seals the deal. Theodosius expels the Arian bishop Demophilus, installs Gregory Nazianzen (then Nectarius), and convenes what we call “Constantinople I.”

It re-brands Nicaea, giving us the Niceno-Constantinopolitan Creed.

Canon 3 gives Constantinople “the primacy of honor after the bishop of Rome, because it is New Rome.”

So Constantinople is honored as second city, but the theological norm has just been defined by appeal to Rome (and Alexandria). From this point on, any story about “the true faith” has to run through Rome. This is the birth of the so-called “Nicene” tradition – 381, not 325.

3. Why Rome suddenly looks like the center (and why Alexandria fades)

Several things converge in the 360s–380s.

The West never really went over to homoian Arianism the way the Eastern court did. That lets Roman bishops later sell themselves as the see that never betrayed Nicaea – but this is with “Nicene” already redefined in Roman terms.

Damasus of Rome (366–384) aggressively develops a Petrine ideology: Rome as the see of Peter, the rock, the court of last appeal. His synods in the 370s–380s hammer this home while the East is still theologically and politically chaotic.

Alexandria, meanwhile, has the huge prestige of Athanasius, but after him the see is torn by internal fights and later by the Origenist/anti-Origenist wars. It’s powerful but provincial, and it never becomes an imperial capital.

Theodosius’s legislation explicitly couples “the religion of Peter at Rome” with imperial orthodoxy. That’s the real transfer of symbolic capital: Rome becomes the legal reference point for what counts as Christian.

Around the same time, the exclusive use of “papa” / “pope” for the Roman bishop solidifies in practice. Earlier the Alexandrian bishop is called “papa” quite naturally; later the title is steadily monopolized by Rome. It’s part of the same slow re-centering of the narrative.

4. Did Constantinople “lose authority”?

In one sense, no: 381 actually elevates Constantinople.

Before 381 it is just the bishop of the imperial residence – powerful because he’s next to the emperor, but not yet canonically ranked.

Canon 3 makes it officially second after Rome.

But in another sense, yes. The kind of doctrinal authority Constantinople had under Constantius and Valens – as the emperor’s mouthpiece for homoian theology – is broken.

After 381:

The emperor’s creed is explicitly tied to Rome (and Alexandria).

The bishop of Constantinople is prestigious but is supposed to be Nicene in the Roman sense. When bishops of Constantinople drift (Nestorius, later Monothelite episodes), Rome and the “Nicene” party can and do present themselves as the court of correction.

So Constantinople wins second place on the seating chart but loses the freedom to define orthodoxy against Rome. Its earlier “authority” as the Arian/homoian capital is exactly what Theodosius’s settlement is designed to overturn.

5. And Sylvester / Nicaea?

This is where the Western story-telling goes into overdrive.

The later picture that makes Sylvester of Rome the great Nicene pope is retrofitted. Sylvester almost certainly did not attend Nicaea; Constantine handled things with Eastern bishops. The council itself is essentially an Eastern affair called by an emperor who favored people we would now call “Arian-leaning.”

Only after 381, when Rome needs a Nicene pedigree, do legends and documents (conciliar acts, “Sylvestrian” stories, eventually the Donation of Constantine) start to re-write the fourth century so that Rome had always been the decisive Nicene seat.

In that retro-narrative:

Nicaea becomes an anti-Arian manifesto (rather than a text that could coexist with Arian and homoian interpretations for decades).

Sylvester becomes the heroic Nicene pope (despite not being there).

Rome becomes the city that had always defined orthodoxy (when in reality Constantinople and the Eastern court were running the doctrinal show for most of the fourth century).

If Constantine favored Arian/homoian theology, and his dynasty did the same, and the Eastern court and bishops were shaped by that, then the natural conclusion is that whatever Nicaea meant in 325, it was not some clear, anti-Arian slogan in the way “Nicene” later came to be defined.

That later “Nicene” – the rigid, Rome-centered version we inherit – looks like a product of the 380s:

An emperor (Theodosius) tying orthodoxy to the “faith of Peter at Rome.”

A bishop of Rome (Damasus) pushing Petrine ideology and retrofitting his see into the Nicene story.

An Eastern capital (Constantinople) being rewarded with second place – but only on condition that it stop being the theological rival and fall into line.

Under Constantine and Constantius, the real doctrinal engine is in the East, centered on the emperor and bishops of cities like Constantinople. After Valens’s death and Theodosius’s accession, imperial power is harnessed to a Roman-defined Nicene orthodoxy (with Alexandria as junior partner).

The Council of Constantinople (381) locks this in: Constantinople is honored, but Rome is the measure.

That is the political and theological shift that, in my view, creates what we now naively call “Nicene orthodoxy” and projects it backward onto 325, as if the whole thing had been settled there from the beginning.