Here's the map I made (PDF download here):
Some of the specific sites and events noted in the map are peculiar to the outings and visits we made as a part of the class. And other things have been left off. But most of the map gives you a nice timeline and visual about the rise and decline of what is called "Celtic Christianity."
To start with some pre-Celtic history, we visited the burial mounds at the Hills of Tara and Newgrange, neolithic sites that pre-date the Celts in Ireland or, rather, the rise of Celtic culture in Ireland.
The origin of the Celts in Ireland is a matter of scholarly dispute. The original Celts were from Gaul (modern-day France, Belgium, parts of western Germany, and northern Italy). The Celts of Ireland and Britain are connected to these European Celts for two reasons. First, the languages of Scotland, Cornwall, Wales, and Ireland are in the Celtic language group. Also, the artifacts of the Celts from the Isles show influences of the La Tène culture of the European Celts. For these two reasons, language and La Tène influence, we describe the peoples encountered by the Romans in the British Isles as "Celtic." These linguistic and cultural features show up in the British Isles between 800-100 BC. So, the neolithic sites of the Isles, like Stonehenge or the burial mounds at Newgrange, pre-date the Celts.
There is some debate about this Celtic "arrival." Was it a migration or invasion of the Isles by the European Celts? Or was it a case of cultural transfusion and change? Historically, the migration/invasion hypothesis was favored. But recent genetic evidence has cast doubt on that theory, pushing scholars toward the cultural change hypothesis. And if that is true, then the peoples of the British Isles were not genetically "Celtic" but became, rather, culturally "Celtic." Either way, the British Isles are recognizably "Celtic" by about 100 BC.
Rome makes it first invasion in 55 BC and eventually comes to establish itself in Britain for a little over four centuries. The Roman impact on Britain remains to this day, from the Roman baths at Bath (shout out to all Jane Austin fans) to the fact that the Brits still drive upon roads laid by the Romans.
Christianity follows those Roman roads to the Isles, making its way to Britain around 200 AD. The faith soon starts to spread. In 300 AD St. Alban dies as the first Christian martyr in Roman Briton.
Roman and Christian influence never fully penetrates to the edges of Briton. Cornwall, Wales, and Scotland remain largely pre-Christian and Celtic. The Romans never invade Ireland, leaving its Celtic culture wholly untouched by Roman culture and the Christian faith.
The Romans leave in 410 AD. After the Roman departure, the Anglo-Saxons begin their migration into East and Southern Briton, effectively taking over the same areas once controlled by the Romans. The Anglo-Saxons arrive as pagans, but they are evangelized by the Christians they encounter. In the Northern parts of Briton, many of these Christians will be the Irish monastics who come from Ireland.
The dawn of Celtic Christianity happens when St. Patrick, around 400 AD, goes back to Ireland to begin his missionary work among the Celts. I say "goes back" because, as a young boy, Patrick had been abducted and taken as a slave to Ireland. Patrick's mission is wildly successful. Christianity spreads through Ireland, and Irish monasticism takes hold in places like Glendalough with St. Kevin, Clonmacnoise with St. Ciarán, and Kildare with St. Brigid. As I noted above, the Irish monks become missionaries themselves. St. Columba establishes the monastery at Iona in 563 AD. In Iona the Book of Kells begins to be created. St. Aidan goes from Iona to Lindisfarne in 634 AD. St. Columbanus goes to France in 600 AD, establishing monasteries throughout Europe. As he travels, Columbanus brings with him the peculiar invention of the Irish monks, the illuminated codex. This impact of Columbanus upon medieval Europe, the monasteries he established with their illuminated manuscripts, is how, in the words of Thomas Cahill, the Irish "saved civilization" after the fall of Rome.
The decline of Celtic Christianity was slow and marked by three main historical events. The first was the Synod of Whitby in 664 AD. One of the aims of the Synod of Whitby was to bring the Irish monasteries under Roman Catholic control. Next, the Vikings began to raid the British Isles around 800 AD. Both Iona and Lindisfarne were eventually abandoned due to Viking plundering. Because of the Viking threat, the Book of Kells was taken away from Iona and brought to Ireland, where it remans to this day. Finally, the Norman invasion of Britain in 1066 AD and Ireland in 1169 AD brought significant Irish influence upon Western Christianity to a close. Given all this, "peak Celtic Christianity" lasted from St. Patrick to the Synod of Whitby, about 250 years. Though distinctive aspects of Celtic Christianity persisted in Cornwall, Wales, Scotland, and Ireland for another 500 years.
So that's the story, told in a single map I made for my students. For more about my take on Celtic Christianity check out Hunting Magic Eels and the chapter on "Celtic Enchantments."
