A key figure in the Arian dispute leading up to and following the Council of Nicaea, Eusebius of Caesarea (bishop c. 313-39) was not only implicated as a central player in the broader theological developments of the early fourth century but was also one of the most significant formulators of ancient literary representations of the council itself. His writings contain an eye-witness account of the council; a broader narrative of Constantine’s interactions with Christian bishops; letters of Constantine addressing issues of theological or practical debate; his own letters to his home congregation at Caesarea and to other bishops involved in the controversy; and his theological polemic against Marcellus of Ancyra, the promoter of a more radical anti-Arian position. These texts simultaneously assist and complicate modern attempts to construct the precise nature and dynamics of the controversy, the council, and its aftermath. They also provide a fascinating angle by which to discern important features of Eusebius’s fertile authorial work: he stands as a careful and creative formulator of a powerful historiographic, theological, and political vision that would make a signal impact upon later competing accounts of the Council of Nicaea.

The main acts of Nicaea were gradually reversed over the years 327-60. Constantine honored its name and canons throughout his life, but recalled Arius from exile, leaned on church leaders to restore him to communion, and sidelined Arius’s opponents. Constantius II flouted Nicaea’s canons and officially replaced its creed. Nonetheless, Nicaea’s pronouncements on the Son’s relationship to the ousia of the Father, including the term homoousios, which had been a response to Eusebius of Nicomedia’s Letter to Paulinus of Tyre, continued to be debated throughout this period in a succession of mutually allusive theological works. These include Eusebius of Caesarea’s Letter to his Church, Eustathius of Antioch’s Against the Arian Madness, Asterius the Sophist’s Defence of Eusebius of Nicomedia, Marcellus of Ancyra’s Against Asterius, Eusebius’s Against Marcellus and On Ecclesiastical Theology, Acacius of Caesarea’s Against Marcellus, Marcellus’ Letter to Julius of Rome, Athanasius’s Orations Against the Arians, the Profession of Faith of Sirmium 351, and Athanasius’s On the Decrees of Nicaea. The last of these, together with his formidable political skills, established the Nicene Creed against all the odds as the only formula which was able to command widespread support among bishops across the empire after the death of Constantius.

This chapter discusses the evidence for the existence of creeds before Nicaea and the purpose for which they might have been employed. The rival accounts of the origin of the Nicene formula are compared, together with the variants in the wording and the different accounts of its origin. The biblical texts that lie behind each verse of the creed are examined, and Beatrice’s argument for a pagan origin of the term homoousios is weighed against other theories. The anathemas require particular study, since the anathema on the term ktiston (“created”) is not preserved in all sources, but is crucial to the argumentation of Athanasius, who claims that it has the authority of Eusebius. The chapter then asks how the Nicene Creed was regarded after the end of the council, and whether subsequent creedal formulations were meant to reinforce or supersede it, and how it attained the form that is now regularly employed in churches.

The Council of Nicaea was a landmark event, yet uncertainty surrounds almost every aspect of the council and its proceedings. No Acts survive, the signatory lists are incomplete, and the organization of the council’s meetings and the identities and motivations of those who participated remain controversial. Rather than propose another hypothetical reconstruction, the aim of this chapter is to reconsider the different interpretations made possible by our limited evidence and the particular questions that have divided scholarly opinion. Who attended the council? Who took the leading roles in the council’s deliberations? And who proposed and supported the crucial decisions, such as the inclusion of the contested term homoousios into the Nicene Creed? Not only are such questions essential to understanding the council and its legacy, but our search for answers offers the opportunity to look beyond the emperor Constantine and the most famous episcopal protagonists, and consider the significance of Nicaea for some of the less prominent figures who contributed to the drama. While their voices are difficult to hear, these more humble individuals had their own parts to play and shared the contemporary awe at a spectacle that symbolized the changing status of Christianity within the fourth-century Roman empire.