A few days ago, I had a chance to visit the Wye valley, which is where an important part of this novel is set, heading for Hay on Wye. In the seventeenth century, it really must have been incredibly remote, because it’s extremely remote even now. It’s one of the most secretive counties in England, because it’s hilly, with huge, tall old trees. Most of the time you can’t see where you’re going. The…

I had to research all kinds of odd stuff for this book. One thing which was surprisingly difficult to imagine was a world without good roads. Roads are one of the most dramatic features of the landscape, the most taken for granted, and central to the way we experience it. In the 1640s, there were mostly routes, some of them very ancient, which isn’t at all the same thing. The Romans had made a network…

Another post on naming, which is one of the things which has to feel right. There are quite a lot of names for fairy kings and queens; due to the shape of my story, I needed several. Most of them are so thoroughly stamped with one particular interpretation that they’re unusable. You can’t have characters called Oberon and Titania without causing A Midsummer Night’s Dream to pop into people’s heads…

The ‘real world’ bit of Secret Commonwealth is peopled with an extensive caste of real people. I was reading John Buchan’s biography of the Marquess of Montrose, who I knew I wanted as a character, when I came across someone else I felt I really had to include; Frances Dalyell. I’ve had hard words to say from time to time about historical fiction which features intrepid heroines engaging in improbable…

Why the name?  -- of course, there’s a natural association between the word ‘Commonwealth’, and the English Civil War, the time period in which the novel is set, which ended in precisely that. But I actually chose my title because of a pre-existing book, The Secret Commonwealth of Elves, Fauns and Fairies. This was written by a Scottish minister called Robert Kirk, in 1691. He was a Gaelic scholar…

One tricky aspect of writing a story which involves non-human entities is that they have to have names and, up to a point, a language. The problems of inventing a language are many and various. First of all, it has to sound right. I wanted something beautiful and a bit strange, but not completely strange. So it had to be basically Indo-European – the language family which includes English, Latin,…

I've often found it true that one book leads to another, even if they're very different. It's hardly obvious that one of the starting points for this particular project was writing the biography of a painter, Edward Burra, who was born in 1905. Burra was no optimist; he had to cope with crippling pain from arthritis and other chronic health problems, and he had a great sense of the darkness of life…