The westward march of Christianity mirrors the arc of empire and civilization itself — from Jerusalem to Rome, and from Rome to the furthest isles and forests of Europe. As empire moved its epicenter westward, so too did the Church, expanding from its Eastern roots into Latin lands where it would shape the soul of the continent. In the cities of Italy, the provinces of Gaul and Spain, the tribal frontiers of Germany, and the windswept coasts of Britain, Christianity laid down roots that would grow into the grand cathedrals and ecclesial orders of medieval Christendom.
Rome: The Nerve Center of Western Christianity
The Church of Rome quickly assumed a role of singular importance in the West. By the middle of the third century, Eusebius records a detailed ecclesiastical structure: one bishop presided over forty-six presbyters, assisted by seven deacons and seven sub-deacons, forty-two acolytes, and fifty others serving as readers, exorcists, and doorkeepers. The Church’s charitable work extended to fifteen hundred widows and the poor under its care. From these figures, it is estimated that the Roman Church had a membership of fifty to sixty thousand — roughly one-twentieth of the city’s population, which likely exceeded one million under the Antonines.
Christian strength in Rome was also manifest in the sprawling catacombs, silent witnesses to both persecution and perseverance. From this metropolitan heart, the faith radiated outward, establishing churches in all the cities of Italy. The first known Roman provincial synod under Bishop Telesphorus (142–154) gathered twelve bishops; by 255, Cornelius convened a council of sixty — evidence of rapid ecclesiastical growth and regional cohesion.
Gaul: The Eastern Connection and Roman Mission
The year 177 marks the fierce persecution of Christians in southern Gaul — a region that had already received the gospel in the second century. The churches of Lyons and Vienne displayed strong connections to Asia Minor, evident in their correspondence with the Eastern churches. Irenaeus, bishop of Lyons and disciple of Polycarp of Smyrna, embodied this East-West continuity.
By the mid-third century, missionary endeavors from Rome intensified. Gregory of Tours recounts that seven missionaries were sent from Rome to Gaul. Among them was Dionysius, founder of the Church in Paris, martyred at Montmartre, and later venerated as the patron saint of France. Later legend confused him with Dionysius the Areopagite of Athens, blurring chronology in favor of apostolic grandeur.
Spain: From Apostolic Hopes to Historic Presence
Though lacking precise records, Spain likely received the Christian faith in the second century. Clear signs of an established Church emerge only by the mid-third century. The Council of Elvira, convened in 306, was attended by nineteen bishops, attesting to a growing ecclesiastical framework.
The Apostle Paul had once envisioned a missionary journey to Spain (Romans 15:24), and Clement of Rome affirms that Paul preached “to the limit of the West” — a phrase traditionally interpreted to mean Spain. While no definitive account of Paul’s work there survives, Spanish tradition vigorously claims him as a founder. An enduring legend even ascribes the evangelization of Spain to James the Elder, despite his martyrdom in Jerusalem in A.D. 44. His purported resting place at Campostella became, centuries later, one of medieval Europe’s most important pilgrimage destinations.
Germany: Hints of Gospel Among the Barbarians
When Irenaeus spoke of “Germans and other barbarians” having salvation written not in ink but upon their hearts by the Holy Spirit, he referred to Roman-controlled regions west of the Rhine (Germania cisrhenana). The deeper penetration of Christianity into Germanic lands would come much later. For now, the gospel glimmered faintly along the borders of imperial order, awaiting fuller dawn in the centuries to come.
Britain and the Celtic Church
Tertullian suggests that Christianity had reached Britain by the end of the second century. There it took a unique form: the Celtic Church — a body that operated independently of Roman ecclesiastical authority for centuries. Flourishing in England, Ireland, and Scotland, the Celtic Christians evangelized not only their own lands but also sent missionaries into Germany, Gaul, and the Low Countries. Eventually, however, the Celtic Church was gradually subsumed into the Roman system.
The origin of British Christianity likely lies in missionary activity from Gaul, and later from Italy. A beloved tradition links it to the Apostle Paul and other apostolic figures. The venerable Bede reports that King Lucius of Britain sought missionaries from Bishop Eleutherus of Rome around 167 A.D. By the time of the Council of Arles in 314, the presence of bishops from Eboracum (York), Londinium (London), and Colonia Londinensium (possibly Lincoln or Colchester) confirms an established and organized Church in Roman Britain.
The Unconverted North and the Coming Middle Ages
While Christianity had spread to many regions of the Western Empire by the third and fourth centuries, large swaths of Northern and Western Europe remained untouched. The evangelization of these lands — the forests of Germania, the fjords of Scandinavia, and the mountains of the Slavs — would not begin in earnest until the fifth and sixth centuries, long after the fall of Rome. That monumental undertaking, full of struggle and sanctity, belongs to the next epoch in Church history — the medieval mission to the barbarians.
