Article

Eyewitnesses to History: The Council of Nicaea in the Ancient Sources

On the 1700th anniversary of the Council of Nicaea · Part 2 of 3

Glen L. Thompson

Wisconsin Lutheran Quarterly, Vol. 122, No. 4 (Fall 2025) · Part 1 · Part 2 · Part 3

Eusebius, Bishop of Caesarea

Our second eyewitness was Eusebius, who had already served for a decade as bishop of the important Palestinian city of Caesarea Maritima, and so was one of the most prominent participants at the Council of Nicaea. It was there that he met Constantine for the first time, and it was probably there that he first came face-to-face with Marcellus of Ancyra, a bishop against whose Christology he would write two books.

His own theological views, somewhat in sympathy with those of Arius, had already caused him to be censured a few months before Nicaea by a council of sixty bishops at Antioch.²⁹ The synodal letter that survives from that meeting reminds us that, until Constantine’s victory in mid-September 324, the eastern emperor Licinius had prohibited church councils for some time in his territories. That is why a synod was urgently needed since “in many places church law has been neglected or even despised, and the decrees which have been passed by other councils have been completely ignored by some worldly men.” The council’s letter includes a creed and anathemas agreed upon by the participants—all, that is, except three, one being Eusebius of Caesarea himself. As a result, it is stated, “all we fellow-ministers in the synod have ruled not to practice fellowship with these men and to consider them unworthy of fellowship, since their faith is something other than that of the catholic church.”

Thus, although he was one of the leading bishops in the entire Greek-speaking church, Eusebius arrived at Nicaea under a cloud of suspicion. In order to clear himself, he put forward what he considered as an improved creed for consideration. However, while not condemned, it was still considered insufficient, and so Eusebius somewhat reluctantly ended by signing the creed containing the word homoousion as produced and approved by the council. He then penned a letter to his own congregation and clergy to explain why he had come to accept the council’s creed. Eusebius himself preserved both his own and the council’s creed in this letter.³⁰

Eusebius returned to Caesarea and would remain bishop there until his death fourteen years later, continuing to be active in regional church councils and in his writing. A decade before Nicaea, he had all but finished his famous Church History. Later he would extend it only as far as Constantine’s victory over Licinius in 324, so it has nothing to say about Nicaea.³¹ However, soon after the council he began work on a eulogistic Life of Constantine that included a description of the council and the emperor’s role in it (3.4–24).³² This work, left unfinished at his death in 339, shows Eusebius’s firm conviction that God had raised up the emperor both to bring peace to the persecuted church and to be a unifying secular supporter of it, and this has caused scholars to be cautious in evaluating his version of Constantine’s participation, acts, and sentiments, including those involving the council.

As befits the work’s purpose as a biography of the emperor, the details about the theological discussions at Nicaea are minimal, instead emphasizing Constantine’s key role in arranging for the meeting, his deference to the bishops, his active engagement in the subjects discussed, and his ongoing involvement following the council. Written about a decade after the council, there is no reason to question the overall accuracy of Eusebius’s description. This work, for example, is our earliest source for two of Constantine’s letters relating to the council: the letter of late 324 to Arius and Alexander trying to settle the matter without a council, and his post-council letter declaring a new unanimity on celebrating Easter.³³

As noted above, the theological aspects of the council are hardly mentioned, and we look in vain for anything in the Life on the christological aspect of Nicaea. However, that is what we should have expected. Eusebius never became a strong supporter of Nicene Christology. In fact, he actively engaged in opposing several of those who did champion it. Christology was at the center of a two-year debate he had with Eustathius of Antioch just after the council, ending with the latter’s removal from office. Meanwhile, when in about 329 Marcellus of Ancyra wrote a tract against Eusebius of Nicomedia and others for their continued support of Arian-type beliefs, Marcellus was also deposed at a council at Constantinople in 336 which Eusebius of Nicomedia chaired.³⁴ At that juncture, Eusebius of Caesarea quickly penned his Contra Marcellum to support what had been done. Then, when Marcellus and other bishops were allowed to return after the death of Constantine (337), Eusebius wrote a more extensive book against Marcellus, On Ecclesiastical Theology. As we might expect, in neither of these two christological treatises does Eusebius ever mention Nicaea or its creed, both of which Marcellus would have defended.³⁵ Thus Eusebius’s contribution to our knowledge of Nicaea is almost entirely limited to his Life of the emperor and his own letter sent from the council.

Eusebius’s Description

Still, even with the above caveats, the Life does provide some useful eyewitness information. Eusebius begins his section on the council by saying that the council was called because of the emperor’s concern over the troubles in Egypt caused by an “envious spirit” and the Melitian schism there (3.4), as well as the “very dangerous disorder” caused by differences over the celebration of Easter (3.5.1). At first the emperor tried to settle the christological matter without a council but “his letter to the Alexandrian Christians failed to produce its due effect” (3.5.3). It was then that he decided to convene a general council (σύνοδον οἰκουμενικήν), calling bishops from everywhere (ἁπανταχόθεν), and encouraging them to use the imperial transportation system (3.6.1). The result was a great assembly of notable church leaders—“the number of bishops exceeded 250, while that of the presbyters and deacons and the many other attendants was altogether beyond counting” (3.8).

The bishops had been arriving over the course of May, with the emperor providing daily provisions for them (3.9). Our sources refer to informal debates taking place as well as more official discussions of the main issues. But Eusebius skips all of this and jumps directly to the emperor’s official arrival in mid-June. “Now when the appointed day arrived on which the council met for the final resolution on the disputed questions, each member was present for this in the central building of the palace” (3.10.1). Eusebius makes it clear that much had already preceded this day, but the emperor who had summoned the council clearly wanted to be present for the final discussions.

The assembly sat waiting expectantly for the emperor’s arrival. Three members of the imperial retinue and some other “friends of the faith” entered first (3.10.2); then all rose as the emperor himself entered “like some heavenly messenger of God . . . distinguished by piety and godly fear.” The bishops then directed the emperor to sit, and they then took their seats (3.10.3–5). A bishop sitting in the place of honor then arose and gave a poetic speech praising and thanking God for the emperor (3.11). Eusebius does not name this welcoming bishop. Theodoret states it was Eustathius of Antioch, while Sozomen names Eusebius himself. Barnes identifies him as Eusebius of Nicomedia. Perhaps more than one bishop gave welcoming speeches.³⁶

The emperor was then given the floor. Eusebius gives a summary version of his speech (“something like the following” [τοῖον ἀπέδωκε λόγον] [3.11]) that was delivered in Latin and then translated into Greek for the predominantly Eastern audience (3.12.1–5).³⁷ In it, Constantine decries “the internal strife within the church of God” and hopes that he “might help find a remedy for this evil” (3.12.2–3). He rejoices in the unity he sees around him and urges the bishops to “begin from this moment to discard the causes of that disunion which has existed among you, and remove the perplexities of controversy by embracing the principles of peace” (3.12.5).

Following this fairly detailed description of the emperor’s arrival and speech, Eusebius puts all the subsequent proceedings into one succinct paragraph:

[Constantine] gave permission to those who presided in the council to deliver their opinions. On this some began to accuse their neighbors, who defended themselves and recriminated in their turn. In this manner countless accusations were put forth by each party, and a violent controversy arose at the very beginning of the council. Despite this, the emperor gave patient audience to all alike, and received every proposition with steadfast attention, and by occasionally assisting the argument of each party in turn, he gradually disposed even the most vehement disputants to a reconciliation. At the same time, by the warmth of his address to all, and his use of the Greek language, with which he was not altogether unacquainted, he appeared in a truly attractive and amiable light, persuading some, convincing others by his reasonings, praising those who spoke well, and urging all to a unity of sentiment, until at last he succeeded in bringing them to one mind and opinion over every disputed question. (3.13)

The length of these discussions is not given, and the eulogistic reflection on the emperor’s role is apparent to the reader. What we can confirm from his description is that there were serious, heated debates on some points, that at times Constantine was appealed to directly, and that the emperor tried to temper the discussion and keep pointing it toward the need for consensus. The mention of his use of Greek probably specifically points to his agreement on the choice of homoousios (ὁμοούσιος) in the christological discussions. Eusebius described that in more detail in his letter to his clergy in Caesarea mentioned earlier (Dok. 24 = Decr. 33):

[Constantine] advised all present to agree to it [i.e., Eusebius’s creed], and to subscribe and agree with its articles, with the insertion of the single word, “of the same being as” [homoousios]. He gave his interpretation of this word, saying that “he [the Son] was not ‘of the same being as’ according to what we experience in our bodies, as if the Son had come to be by dividing or breaking off from the Father. For his nature could not be subjected to any bodily experiences, as it does not consist of matter, exists in a spiritual realm, has no body. Therefore such things must be thought of in divine, unspeakable concepts.” Such were the theological remarks of our most wise and most pious Emperor; but they were intent on adding the word “of the same being as” and drew up the following statement. (7)

Then, after giving the text of the creed which the council did approve, Eusebius continues in his letter:

As this formula was being debated, we made sure to inquire in what sense they introduced “from the essence of the Father,” and “of the same being as the Father.” Through intense questioning and explaining, the meaning of the words was examined closely. They explained that the phrase “of the same being as” indicated that the Son is truly from the Father, but he is not a part of him. (9)

and shortly afterward:

So when we considered it, we found that there are grounds for saying that the Son is “of the same being as” the Father; not like human bodies, nor like mortal beings, for he is not “of the same being as” by dividing his essence, or by cutting something off, or by having something done to him, or being altered, or by changing the Father’s essence and power (since the Father’s nature has no beginning to its existence, and therefore none of those descriptions apply to it). (12)

Thus Eusebius summarizes the emperor’s position in a way that aligns with his own reasoning for accepting homoousios. While we may be a bit skeptical about how accurately Eusebius reproduces the emperor’s reasoning, this testimony would seem to indicate that the emperor did engage in the theological discussion, seemingly with some substantial background in the issues. Again, his concern was not only about arriving at a sound Christology, but that unity and harmony be reached.

Eusebius then concludes his description of the council in his Life of Constantine as follows:

The result [of the discussions] was that they [the bishops] were not only united as concerns the faith, but that the time for celebrating the feast of Easter was agreed on by all. Those points on which all agreed were also committed to writing, and received the signature of each member. Then the emperor, believing that he had thus obtained a second victory over the adversary of the Church,³⁸ proceeded to celebrate a triumphal festival in honor of God. (3.14)

The “points agreed upon by all” and “committed to writing” were not only the creed but also the twenty canons of the council that have been preserved.³⁹ Constantine then included all the bishops at the lavish banquets and festivities celebrating his twenty-year rule and personally gave them each gifts (3.15–16). Finally the emperor composed a letter “in his own handwriting” addressed to “the churches” in general, informing them of the conciliar decisions. At this point Eusebius includes the full text of the letter, which is principally about the agreed policy for celebrating Easter (Dok. 30; 3:17–20). Note that Eusebius does not append the imperial letters having to do with Arius. Again the Life can be faulted for what it omits rather than for what it includes about the council.

Eusebius closes by describing how the emperor gave a final address to the bishops before they headed home (3.21). By inserting the text of the letter before this notice, Eusebius seems to imply that the bishops carried copies of the letter to distribute to those bishops who were not in attendance. Eusebius claims to provide the gist of this farewell speech;⁴⁰ as expected, he again stresses the importance of harmony, unity, and humility. And so it happened, writes Eusebius, “from then on that unity of judgment at which they had arrived in the emperor’s presence continued to prevail, and those who had long been divided were bound together as members of the same body” (3.21).

However, he is forced to modify this optimistic assessment in the very next section of the Life where he admits that in Egypt a “relentless conflict still raged, so as once more to disturb the emperor’s tranquility,” requiring yet more imperial involvement and further letters (3.23).

Continued in Part 3 →

Notes

²⁹ Dok. 20. This council must have met in the very last days of 324 or the first days of 325 or both. It was undocumented until a Syriac manuscript of its synodal letter was published by Eduard Schwartz in 1905, in “Zur Geschichte des Athanasius, V.”, 272–79 (Syriac text and retroverted Greek translation; reprinted in Schwartz, Gesammelte Schriften, 3:136–43). The quotes are from sec. 4 and 14; the council’s creed is in sec. 8–12, with the anathemas following in sec. 13.

³⁰ Eusebius’s letter is Dok. 24 = Decr. 33. His creed is in sec. 4–5 while the council’s is in sec. 8.

³¹ T. D. Barnes has argued that books 1–7 were written by the end of the third century, 8–9 were added following the Great Persecution in 313/314, and 10 was added soon after but later updated to conclude with Constantine’s final unification of the Empire in 324 (Constantine and Eusebius [Cambridge, MA: Harvard University Press, 1981], 126–50).

³² 3.4–24. About the same time as he was writing the Vit. Const. he was also composing his Contra Marcellum, which also involves Christology. While he doesn’t directly describe the council in his work, several excerpts from the pre-council controversy (Dok. 5, 10, 21) were preserved in this work, with 5 and 21 surviving only in this way.

³³ Dok. 19 = Vit. Const. 2.64; Dok. 30 = Vit. Const. 3.17–18.

³⁴ Marcellus also refused to accept the deposition of Athanasius by the Council of Tyre in 335.

³⁵ The Contra Marcellum is our source for two or three of the pre-council Dokumenten. Within the extensive quotes from Marcellus are embedded several quotes from a letter of Paulinus (Dok. 5); from a letter of Narcissus to Chrestus et al. (Dok. 21); and an excerpt from Eusebius’s own letter to Euphration of Balanea (Dok. 10).

³⁶ Theodoret, Eccl. hist. 1.7.10; Sozomen, Eccl. hist. 1.19.2; T. D. Barnes, Constantine: Dynasty, Religion and Power in the Later Roman Empire (Chichester: Wiley-Blackwell, 2011), 121. Averil Cameron and S. Hall also seem to opt for Eusebius of Nicomedia, stating that this was in a chapter heading (Eusebius: Life of Constantine [Oxford: Clarendon, 1999], 265), but the editions do not have chapter headings, and the κεφάλαια list only has “Eusebius the bishop” in the standard edition of F. Winkelmann (Über das Leben des Kaisers Konstantin, 2nd ed., GCS, Eusebius Werke 1.1 [Berlin: Akademie-Verlag, 1991], 8). However, although Nicomedia was an important nearby bishopric, and site of another imperial palace where Constantine spent considerable time while Constantinople was still under construction, the emperor’s relationship with its bishop (who had been a supporter of Licinius; see above) would not make him a natural choice for this duty. Eusebius of Caesarea, being under a cloud since the Council of Antioch earlier in the year, would also seem to have been an unlikely candidate. Therefore, perhaps Eustathius of Antioch is the most likely of the three, or there may have been two such addresses.

³⁷ An analysis of the list of 220 bishops who attended shows that about 90 percent came from Greek-speaking areas, 5 percent from Latin-speaking areas, and 5 percent from Syriac-speaking areas.

³⁸ Eusebius’s biography makes it clear that the rival emperor Licinius was the first adversary that Constantine overcame, and that he was also an adversary of the church.

³⁹ Rufinus of Aquileia translated Eusebius’s Eccl. hist. into Latin and then expanded it with two extra books, including mention of Nicaea. He is the first to preserve the canons, though he provided only an epitome of each. The Anonymous Church History, composed about 475, seems to be the earliest surviving source for the complete text of the canons.

⁴⁰ τοιαῦτα μὲν ἐν πρώτοις παρῄνει, τέλος δ’ ἐπετίθει τὰς ὑπὲρ αὐτοῦ πρὸς τὸν θεὸν ἱκετηρίας ἐσπουδασμένως ποιεῖσθαι (3.21).