The earliest extra-biblical surviving historical record of the Church comes from Eusebius (c. 260-339), a bishop of Caesarea in Palestine. For that reason alone, Eusebius’s History of the Church is essential reading for anyone seeking to understand the first three centuries of Christianity. And, as even a cursory study of his ten-chapter work shows, there is much to confirm a singularly Catholic understanding of the Church.
It’s important to acknowledge Eusebius’s shortcomings. The fourth-century bishop was an overt advocate and defender of the emperor Constantine (the tenth chapter of his history is a not so subtle paean to the emperor), which provoked criticisms from later Church historians that Eusebius was a bit of a toady and his writings too politicized. He was an early supporter of the heretic Arius, leading to accusations that he was himself an Arian. (Eusebius was later exonerated of the heresy charges with the approval of Constantine at the Council of Nicaea.) And his history has been the object of much criticism, with many scholars, including the great patristic scholar William Jurgens, noting various historical errors in Eusebius’s work.
Nevertheless, despite these legitimate concerns, it’s hard not to overstate the value of The History of the Church. It is the first extra-biblical history of the Church. (Luke’s Acts of the Apostles is the first ecclesial history.) Even with various errors, modern scholars, Catholic and non-Catholic alike, recognize Eusebius’s work as invaluable to understanding the early Church. Indeed, in many cases, we are aware of other early Church thinkers (and their writings) because the Cesarean bishop cites them. And, whatever error Eusebius made, there is also plenty in his history that is confirmed by other ancient sources. Thus, whatever broad trends we can decipher from The History of the Church are incredibly important for us as we contemplate Christianity in its first three centuries.
There are several key themes in Eusebius’s history that illuminate the identity and interests of the early Church. The first of these is the centrality of apostolic succession. Eusebius begins the chapter, or book, noting the “chief matters” he intends to address in his work, and at the top of his list is “the lines of succession from the holy apostles, and the periods that have elapsed from our Savior’s time to our own.” Thus, throughout his history, we find reference to apostolic succession in Jerusalem, Antioch, Alexandria, and Rome (what are called patriarchates).
Eusebius at one point cites a churchman named Gaius, who not only claims to know where the monuments to Ss. Peter and Paul lie, but also refers to the two as “those who founded this church.” Eusebius also refers to Alexander as “fifth successor to Peter and Paul.” He cites the second-century “Easter Controversy,” over the dating of Easter, noting that bishops in the East—as well as Irenaeus, bishop of Lyon—disagreed with the Roman bishop (that is, the pope) Victor over his decision to excommunicate some dioceses in Asia Minor. Yet even in his criticism of Victor, Eusebius implies that he and Irenaeus both recognized the Roman bishop to possess an authority to excommunicate, since “he [Victor] should not cut off entire churches of God.” Moreover, Eusebius refers to Peter as the first bishop of Rome and describes how the great theologian Origen felt the need to prove his orthodoxy to Fabian, bishop of Rome.
A second central theme of the history is the repudiation of heresies. Among the heretical groups Eusebius discusses are the Ebionites, who rejected Christ’s divinity; the Montanists, charismatics who believed in new prophetic revelations; the Novatians, who refused readmission to lapsed Catholics; and the Sabellians, who believed that the Father, Son, and Holy Spirit were three distinct “modes” of God. In each case, Eusebius repudiates heretics because they are not faithful to Scripture or the traditions of the apostles preserved through their successors, the bishops. For example, the historian mentions Pope Stephen and unnamed synods of bishops as authorities in the debate over baptizing lapsed Christians.
This emphasis on alignment with apostolic teaching preserved through the episcopacy is also relevant to a third critical theme in Eusebius: the persecution of the early Church and the coeval significance of martyrs. Every chapter of the history contains stories of martyrs, and some, like book nine, contain little else. Eusebius points to their value in his citation of Justin Martyr, who writes, “When I found them [Christians] fearless in the face of death and all that men think terrible, it dawned on me that they could not possibly be living in wickedness and self-indulgence.” In other words, martyrs served as an effective, provocative testimony—the Greek word literally means “witness”—to the veracity of the Church’s claims.
Yet Eusebius recognizes that there is a potential problem with this “motive of credibility”: some heretical groups also claimed martyrs, such as the Marcionites or Montanists. The historian in response cites an unnamed Christian writer who argues that false martyrs are those who “do not truly acknowledge Christ,” and with whom members of the Church refuse to fellowship. In effect, true martyrs are those in communion with the true Church, and, by extension, the true Church is identified by apostolic succession.
There are other currents in The History of the Church worth exploring. Eusebius’s descriptions of the sometimes acrimonious debates over the dating of Easter will likely surprise twenty-first Christians (especially non-Catholics), who place less of a premium on the liturgical calendar. His hagiography of Origen evinces his theological leanings. But the themes of apostolic succession, combating heresy, and celebrating martyrs loom largest across the text. And, regardless of the historicity of Eusebius’ various accounts, the work demonstrates what issues and controversies dominated the first three centuries of the Church.
In sum, the early Church put a pedigree on apostolic succession, not only as a means of identifying the true Christianity against false imitators, but also to recognize its true martyrs. Certainly, Eusebius also believed that heresies could be refuted by reference to Holy Scripture, but it was the apostolic Church that was Scripture’s faithful protector and interpreter. And that the Roman bishop—beginning with Peter but continuing with such figures as Clement, Stephen I, Sixtus II, and Fabian—is so central to the debates of the early Church is at least suggestive of the growing recognition of the pre-eminent authority of the Roman see in the early centuries.
Whatever its historical limitations, Eusebius’ The History of the Church quite demonstrably shows that the early Church was a singularly Catholic institution.