By the time of the Edict of Milan (313) Christianity had survived in an empire that had been at best indifferent to it and at worst actively hostile for nearly 300 years. Its origins, like so many of the religious beliefs that spread into the Graeco-Roman empire after the first century, lay in the east. It focused on the worship of Jesus, a Jew who lived and preached in Galilee, part of Palestine, before being crucified in Jerusalem in the reign of Tiberius. (Jesus, derived from the original Aramaic Yeshua, was his given name—Christ, from the Greek Christos, the messiah or anointed one, came to be used when his movement spread into the Greek world.)
This is an exciting area of scholarship where conventional approaches and interpretations are likely to be challenged in future years as archaeology and texts are combined to provide a more nuanced picture of Christian growth. In recent years, biblical scholars have become noticeably more relaxed about works that challenge traditional accounts of the ‘inexorable’ rise and ‘triumph’ of Christianity and more ready to accept the undoubted diversity of Christian belief as it was accommodated, or accommodated itself, into different cultural and linguistic niches. Christianity took many different forms as it confronted or compromised with the varied cultures of the Mediterranean. A view, still to be found in some traditional histories, that the spread of Christianity was a smooth, steady, and inevitable process, does not accord with the sources. Congregations flourished in some areas but not in others. Many early communities, known from the letters of Paul, disappear without trace. Nor was persecution persistent. There were persecutions of Christians in the 250s (the emperor Valerian) and early 300s (Diocletian) but a long period of comparative toleration in between. Yet, despite the periods of peace, tensions between different Christian groups were so great in the late third century that the historian Eusebius claimed that God brought about Diocletian’s persecutions as a punishment. (See the opening paragraphs of his The History of the Church, Book VIII.)