The Arrival of Christianity in Ireland: The Romans and Saint Patrick


By Jennifer Paxton, Ph.D., The Catholic University of America

The view of Celtic Christianity has changed a lot in the past few years. It used to be thought that a fair amount of Celtic paganism was preserved in Celtic Christianity, but scholars are now far less sure about this. How was Christianity brought to the Celtic lands, particularly Ireland?

Simple one-room church of stone from the period of early Christianity in Ireland.
The earliest churches in Britain were probably simple structures such as this ancient Irish church. (Image: Mike Lord/Shutterstock)

Roman Britain and the Spread of Christianity

The first of the Celtic areas to be Christianized as far as is known was Roman Britain. There is evidence for Christianity in Roman Britain from as early as the 3rd century A.D., possibly slightly earlier.

Since Britain was very tightly connected to Roman Gaul at the time, the presumption is that missionaries from Gaul brought the Christian faith to Britain, where it first took root in the urban areas and then spread out into the countryside.

Chi-Rho symbol in red against a white background on a wall.
This Chi-Rho symbol was discovered in a Roman villa in England, indicating that this part of the house was used as a chapel. (Image: I, Udimu/CC BY-SA 3.0/Public domain)

There is evidence of dozens of Christian churches, some only chapels in houses, having existed during the period of Roman rule. There was a spectacular find in 1975 at Water Newton in Cambridgeshire of objects that may have come from a local church, including a large silver cup that may have been a liturgical vessel and a silver votive plaque containing the Christian Chi-Rho symbol.

Learn more about pre-historic Ireland and the Celts.

The First Irish Christians

In the case of Ireland, the first people to bring Christianity may have been, not missionaries, but Christian slaves brought to Ireland against their will. This was also a period when some Irish dynasties, particularly in the south and east of Ireland, were establishing branches in western Britain, and they may well have encountered Christians there and brought the faith back.

However, it spread, there were enough Christians in Ireland that in 431, Pope Celestine sent a bishop named Palladius from Gaul to Ireland to minister to “the Irish believing in Christ”. So, the Christian community by this point must have numbered in the hundreds at least, and it must have been vocal enough to be heard all the way to Rome.

Palladius duly went to Ireland, and he seems to have had several disciples as well, and all of them founded churches, mostly in the southeast. Very little is known about their work, unfortunately, because no written sources about their mission have survived. That is emphatically not the case for another very important traveler to Ireland: Saint Patrick.

This is a transcript from the video series The Celtic World. Watch it now, Wondrium.

Saint Patrick’s Early Life

Saint Patrick was a Romano-British youth who was captured by Irish raiders and brought to Ireland, where he served his master for six years, tending sheep, probably in the northern part of Ireland. While he was alone with the sheep, he received a divine call to escape from captivity, become a priest, and return to convert the Irish.

And that is what he did. Saint Patrick managed to get taken on board a ship that sailed somewhere that might have been Gaul. But he ultimately made it back to Britain, where he then studied for the priesthood. Then he took it upon himself to return to Ireland to preach the gospel.

Learn more about Celtic churches.

Saint Patrick’s Evangelical Mission

A colorful stained glass window showing Saint Patrick.
Saint Patrick was responsible for the growth of Christianity in Ireland. (Image: Nheyob/CC BY-SA/4.0/Public domain)

We know about Saint Patrick’s mission from the two texts that he wrote. One was his ‘Letter to Coroticus’ which was addressed to the British or Pictish slave trader who had stolen some of his newly baptized converts. But it is the other text, Saint Patrick’s Confessions, where he writes more in general terms about what his mission was actually like.

At the time, Ireland had many small independent kingdoms, Saint Patrick describes going around preaching to each kingdom individually. It was much easier to convert larger political entities, where if the king accepted the new faith, he would bring the nobility with him, and so on. In Ireland, this process took many small acts of evangelism rather than a few large ones.

The Growth of Christianity in Ireland

At some point in the early 5th century, other missionaries brought the monastic movement to Ireland, possibly from both southwestern Scotland and Wales. The decentralized nature of monastic churches fits very well with the Irish political landscape. Christianity in Ireland was thus solidly grounded, thoroughly integrated into the life of the country, but not organized along the kinds of hierarchical lines that would be more typical on the European mainland.

Common Questions about the Arrival of Christianity in Ireland

Q. Who were the first people to bring Christianity to Ireland?

The first people to bring Christianity to Ireland may have been Christian slaves who were brought to Ireland against their will. Another possibility is that the Irish who were extending their links into England encountered Christianity and brought it back with them.

Q. Who was Saint Patrick before he became a priest?

Saint Patrick was a Romano-British youth. He was captured by Irish raiders and brought to Ireland as a slave. He served his master for six years, tending sheep, probably in the northern part of Ireland. While he was alone with the sheep, he received a divine call to escape from captivity, become a priest, and return to convert the Irish.

Q. Why was it more difficult to undertake evangelism in Ireland?

Ireland had many small independent kingdoms, unlike the larger kingdoms of the Anglo-Saxon rulers. Thus, Saint Patrick had to visit each kingdom in turn to preach, which was a lot of hard work.

Keep Reading
Pre-Christian Ireland: The Scholarly Views
The Origins of the Celtic Picts
What Happened to Britain After the Romans Left?