Sunday, 15 February 2026

In Search of St Tysilio

 Many readers will know that my happy place is North Wales, and that all of my novels feature Welsh characters. This is no indulgence; I write about the erstwhile midlands kingdom of Mercia, and Mercia shared a border with Wales. And today I want to talk about a little connection I found on a recent visit.

In the dark days of January I took myself off for a mini-break, just over the Menai Strait onto Ynys Môn (Anglesey). Usually I travel all over the island, but this time I stayed at Menai Bridge and also decided to leave my car in the hotel car park and explore - on foot - a place that I usually just drive through on my way to other spots on Môn.

Menai Suspension Bridge

I'm sure everyone is familiar with the two famous bridges, Menai Suspension Bridge itself (designed by Thomas Telford) and the newer Britannia Bridge, designed by Robert Stephenson (son of George). I've driven over both, plenty of times, but never explored underneath.

Walking through the town of Menai Bridge I popped into a shop, POM, made a few purchases, and got chatting to Phillip who kindly gave me directions to Church Island.

What a delight this place is. Although it's called an Island, there is a permanent causeway so you don't get your feet wet. It's just off a section of the Wales Coastal Path, and I have rarely been in such a peaceful place.

Looking out towards Church Island and beyond to the Britannia Bridge

The information board told me that regular services are still held in the church, which was founded by St Tysilio and actually in Welsh this place is not called Church Island but Llandysilio Island or, I imagine, more correctly Ynys Tysilio .

What struck me most, aside from how beautiful this church is, was the date it was supposedly built: 630AD. This would mean that it has been there since around about the middle of King Penda of Mercia's reign - a man about whom readers of my blog and books will know I've written a great deal. However, as far as I can discover, the present building actually dates to the 15th century, but may well have been built on the same spot as Tysilio's hermitage.

Sadly the church was locked so I was unable to look inside, and had to wait until I came home to research St Tysilio. His name seemed familiar, somehow... (I'll come back to that).

It seems that, as is often the case with early Welsh saints, Tysilio was royal, said to be the son of Brocmail, a prince of Powys. His genealogy is mentioned in the Bonedd y Saint (The Descent of the Saints), compiled in the twelfth century.

There is no 'Life' for him that still exists. It doesn't mean there wasn't one, of course, and I'm aware of plenty for English Saints - Felix's Life of St Guthlac - a Mercian hermit - for example. He was mentioned in the 'Life' of another saint, Beuno, and I like this link because my first ever visit to Wales was when I stayed at Clynnog Fawr, location of the beautiful church of St Beuno. (We also know that Ælfhere, real life character on which my Alvar the Kingmaker was based, was in Clynnog Fawr in 978.)

St Bueno's Clynnog Fawr - Commons attribution link

St Tyslio came to be associated with the community at St Suliac in Brittany and his story became entwined with Suliac's. In this legend, it is said that after Tyslio had founded his church of Llandysilio he went home to Meifod in Montgomeryshire, but was pestered mercilessly by his sister-in-law and fled to Brittany where he founded St Suliac's. It does seem as if these two saints' stories have been conflated and there is no evidence that Tyslio ever left his native Wales. 

And in fact, he's more famous that you might suppose, and not in the way you might think. I said I'd come back to his name...

Drive over the Menai Suspension bridge and turn right, and you come into the town of Menai Bridge. Drive over the Britannia bridge and turn left and you soon come to probably the most famous of all Welsh places:

Commons attribution link

As you might already know, this isn't strictly speaking a 'genuine' name, but was made up as a sort of marketing ploy in the 19th century. But whilst it's a difficult word to say, and hard to understand if you don't speak Welsh, let's break it down, in its most usual translation:

The church of St Mary (Llanfair) [of the] pool (pwll) of the white hazels (gwyn gyll) near to (go ger) the fierce whirlpool (y chwyrn drobwll) [and] the church of St Tysilio (Llantysilio) of the red cave (gogo[f] goch).

So next time you're practising saying this out loud (you don't? Just me then!) remember that it incorporates Llantysilio*, and it refers to the beautiful building on Church Island in the Menai Strait, built when King Penda was at the height of his powers just over the border!


*Llandysilio/Llantysilio - I've seen both versions of this in the course of my research and I'm not sure why. I know enough Cymraeg (Welsh) to understand that this shift from Tysilio to Dysilio is probably because of a mutation. Nine Welsh letters mutate in certain grammatical instances, but I'm not competent enough to explain all that just yet. You see the same thing with Llandudno, where you'll find the church of St Tudno on the Great Orme.