A Church History Series: Anglicanism – Ancient Celtic Church Before Augustine

Christianity Before Augustine: The Ancient Celtic Church of Britain

Many people assume that Christianity arrived in Britain with Augustine of Canterbury in 597. The reality is far older and far richer. When Augustine stepped foot in Kent, he found:

• a Christian queen already on the throne,

• bishops active in the land,

• and a church with centuries of life behind it.

To say that Christian history in Britain began with Augustine of Canterbury in 597, would be like saying that human history in North America began with the founding of Jamestown, VA in 1607.

For the English Reformers, this history mattered deeply. The Church of England was not a new creation but a reformed continuation of the ancient British Church—a church that had existed long before Roman authority ever entered the islands. And this early British Christianity—often called the Celtic Church—was known for three powerful characteristics: missionary passion, serious learning, and a striking simplicity of life.

What Do We Mean by “The Celtic Church”?

The term refers to the Christian communities that spread across the British Isles before Augustine’s Roman mission in the late sixth century. While its exact beginnings are lost to time, Christianity was firmly established by the end of the second century.

The historical evidence is compelling:

Early Testimony

• Around 201 A.D., the theologian Origen remarked with astonishment that even places in Britain untouched by Roman rule had come under the influence of Christ.

• Gildas—Britain’s earliest historian—and Bede both recount the martyrdom of St. Alban, Britain’s first recorded martyr, during the persecution of 305.

British Bishops at the Early Church Councils

• At the Council of Arles (314), three British bishops were present—York, London, and Lincoln—accompanied by clergy. Such participation shows a well-organized church able to send delegates across Europe.

• At the Council of Ariminum (359), three more British bishops attended. They were the only Western bishops who accepted the emperor’s offer to pay for their travel, likely reflecting the modest means of their congregations.

A Recognized Part of the Christian World

Major church leaders—Athanasius, Chrysostom, Jerome—all recognized British Christians as faithful to the orthodox creed.

Archaeology adds to the picture: the ruins of a stone church in Silchester, similar to fourth-century churches from across the Mediterranean, testify to a connected Romano-British Christianity.

Long before Rome sent missionaries, Christian Britain was already alive and active.

The Spiritual Landscape of the Celtic Church

The wider Christian world of the early centuries produced theologians and writers whose texts shaped centuries of doctrine. The British Isles produced missionaries, monks, and saints whose legacy was found not in books but in transformed communities and heroic deeds.

Ninian (c. 360–432)

Born in Cumbria and educated in Rome, Ninian returned home burned with missionary zeal. Inspired by St. Martin of Tours, he founded Candida Casa (“White House”) in Galloway—a monastic base that influenced generations of Celtic evangelists.

Pelagius: A Troubling Native Son

The British monk Pelagius gained fame for his strict moral teaching, but notoriety for minimizing humanity’s dependence on divine grace. His teachings provoked vigorous responses from Augustine and Jerome, eventually leading to his condemnation. His prominence, however, shows the intellectual vigor present in the British Church.

Patrick (c. 385–461): The Apostle to Ireland

Though remembered as Ireland’s patron saint, Patrick was a Briton. After escaping slavery in Ireland, he trained for ministry on the continent and returned as a missionary filled with courage and charity. He:

• confronted pagan powers,

• founded churches and monastic centers,

• established Armagh as a center of Christian learning,

• and ignited a spiritual movement that shaped Ireland for centuries.

Patrick embodied the Celtic virtues: scholarship, artistic imagination, strict discipline, and passionate mission.

Columba (521–597): The Flame of Iona

After a violent conflict in his youth, Columba vowed to dedicate his life to Christ. With twelve companions he sailed to the island of Iona, founding a monastery that became one of Europe’s greatest missionary centers.

From Iona:

• Scotland was evangelized,

• Pictish kings were converted,

• and missionaries traveled to England and continental Europe.

Columba’s character combined fierce intensity with astonishing gentleness—earning him the name “the Dove.”

His death in 597 came only weeks before Augustine’s arrival in Kent.

Celtic Christianity vs. Roman Christianity: A Tale of Two Approaches

The Celtic Church differed sharply from the Roman model:

Celtic Christianity

• Monastic, not diocesan

• Authority vested in abbots rather than bishops

• Highly ascetic and communal

• Emphasis on mission, pilgrimage, and personal holiness

• Independent of Roman jurisdiction

Roman Christianity

• Structured around dioceses and hierarchy

• Strong emphasis on Roman oversight

• Greater uniformity in liturgy and practice

• Administrative order and central authority

These differences sometimes surfaced in surprisingly small ways—how monks cut their hair, how Easter was calculated—but they reflected far deeper contrasts in worldview and practice.

The Anglo-Saxon Crisis—and the Great Missionary Revival

Beginning in the mid-fifth century, Anglo-Saxon tribes poured into Britain, displacing or annihilating many Celtic communities. The remaining Celts retreated to Wales, Cornwall, and the north—and tragically refused to evangelize the newcomers.

The result: paganism reclaimed the land.

Christianity returned through two great missionary movements:

1. The Roman mission under Augustine (597), centered in Canterbury.

2. The Celtic mission from Iona, which would evangelize northern and central England.

Although the Roman mission eventually gained institutional dominance, the Celtic mission had a profound spiritual impact.

Aidan of Lindisfarne: A Celtic Light in Northumbria

After a year of devastating warfare, the Northumbrian prince Oswald, who had lived in exile at Iona, reclaimed his kingdom in 634. Desiring to restore Christianity, he turned to the monks who had nurtured him.

The first missionary sent from Iona struggled, but a monk named Aidan explained why: the preacher had been too harsh. Impressed, the community sent Aidan instead.

Aidan:

• refused to base his ministry in York and chose Lindisfarne, mirroring Iona’s spiritual solitude

• lived simply and gave generously

• preached with patience and clarity

• partnered with King Oswald, who often interpreted his sermons

• ignored Roman claims of authority and worked as a missionary of the Celtic Church

From Lindisfarne emerged a century of astonishing Christian renewal in northern England—monasteries, schools, evangelists, and saints.

A Legacy Worth Remembering

The story of Christianity in Britain does not begin with Augustine. It begins centuries earlier—with Christians who prayed, studied, evangelized, and suffered for their faith long before Rome asserted authority over the islands.

The Celtic Church was:

• mission-driven

• deeply learned

• radically simple

• spiritually vibrant

• independent of outside control

For the Reformers, this ancient inheritance was proof that the English Church had not been born from Rome, but reformed into a renewal of its earliest roots.

Today, the story of the Celtic Church invites us to see Britain’s Christian past—one filled with courage, creativity, and enduring faith.