The cartographic material we present on the feast day of Saints Peter and Paul, created by our colleague, Dr. Daniel Iosif, illustrates the process of geographical expansion that transformed a local religious movement that emerged in first-century Palestine into a universal religion that came to dominate the Mediterranean basin.
Christianity emerged after the execution of Jesus of Nazareth around A.D. 30 under the Roman governor Pontius Pilate. While its first communities formed in Jerusalem, its actual expansion began with local persecutions and the dispersal of believers who carried the message further into Syria, Cilicia and beyond.
The central figure of this dissemination was the Apostle Paul (Saul of Tarsus), who undertook four major missionary journeys between A.D. 46 and 62. The first (46–49 CE) took him, along with Barnabas, to Cyprus and southern Asia Minor, where they established mixed communities of Jews and non-Jews. Paul's second journey (49–52 CE) focused on Macedonia and Achaia (Athens, Corinth), where he adapted his message to a Hellenistic audience, as seen in his famous speech at the Areopagus. His third journey (A.D. 53–58) focused on Ephesus, the commercial and spiritual metropolis of Asia Minor, wherefrom he coordinated several regional missions and wrote important epistles (to the Corinthians, Galatians, and Romans). His final journey, as a prisoner, took him to Rome, passing through Malta after having been shipwrecked, marking the Christian presence in the Roman Empire's capital shortly prior to his martyrdom around 64–67 AD under Emperor Nero.
Further east, the metropolis of Antioch in Syria quickly became the second major center of Christianity after Jerusalem; indeed, it was here that the term "Christians" was first used. In Egypt, Alexandria also developed a profound theological tradition, through a catechetical school led by Pantænus, Clement, and Origen. The Christians of Rome, initially a community likely founded by Jewish converts, gained special authority owing to the martyrdoms of Peter and Paul. For its part, Constantinople gained importance after Constantine the Great relocated the imperial capital to the former Byzantium. Notably, Armenia marked an absolute milestone, becoming the first state in the world to adopt Christianity as its official religion in 301 AD, following the efforts of St Gregory the Illuminator under King Tiridates III.
The pre-Constantinian period was marked by waves of persecution against Christians: under Emperors Nero (64 AD), Domitian, Trajan, Decius (250 AD), and Diocletian (303–311 AD), with the latter being the most systematic purger of Christian beliefs. Nevertheless, the new religion continued to spread through trade networks, the military and family ties, becoming especially attractive to the urban middle classes, slaves and women through its message proffering spiritual equality and eschatological hope. The Edict of Milan (313 AD), issued by Constantine and Licinius, brought the faith into legality, while Theodosius I's Edict of Thessalonica (380 AD), later established Christianity as the sole state religion of the Roman Empire.
