SOLVED. Medieval Wales and today's London, hypnotised and gets thrown back in time [s]

[MikeyIdea]

Hi,
I read a very interesting novel about 25 plus years ago. The book is about a woman (or was it a man, not sure) who lived in London, she (he?) is hypnotised and gets thrown back in time to medieval Wales, she (he) even speaks medieval Welsh when that happens but can't remember a word of it when woken up of the hypnosis. I also remember that there was quite a bit about a cathedral that failed (crashed down killing a lot of people), and I got the feeling that the author had a special interest in that area.

I also remember Abergavenny, setting in a medieval castle. I was a member of a British book club and got it sent to me 26-27 years ago. I'd really want to read it again but my memory has failed me

Please help out, what was the name of the book or the author?
Thank You
Michael

[Juels]

Lady of Hay by Barbara Erskine?

https://www.goodreads.com/book/show/1...

[MikeyIdea]

yes, that's the one

Thank You Very Much
Michael

[Juels]

You're welcome.