PW: What was the genesis of Jonathan Strange & Mr Norrell?

When I was a child, I loved books with magic in them. Then at the beginning of the '90s, I'd abandoned a detective novel I was writing, partly because I couldn't get the plot right and partly because a weird, fantastic, slightly surreal atmosphere kept creeping in—quite wrong for a detective novel. I was teaching English in Bilbao, and I became ill with some sort of postviral thing. This necessitated resting a lot. So I bought The Lord of the Rings and reread it. Then I reread it again. It completely took me over, and by the time I'd finished, it was obvious I ought to try writing a novel of magic and fantasy.

In this novel, you've created an alternate history of Great Britain in which magic is a historical fact. Do the Raven King or any of the lesser magicians have any precedent in actual English history or folklore?

There's only one real magician among them. He's Valentine Greatrakes. What a fantastic name. He was a celebrity Irish healer who toured England in 1666 and cured a number of people by the laying on of hands. Everything else I made up. I was keen to get as much actual folklore into Jonathan Strange & Mr Norrell as I could—particularly in regard to fairies—but it wasn't easy. What's come down to us about our ancestors' fairy beliefs is very hard to catch hold of. My fairies begin life inhabiting hollow hills. That's pretty authentic, and so is their propensity to steal Christians.

How accurate are your descriptions of the battles of the Napoleonic Wars and London politics of the period?

I've spent a great deal of time trying to get the detail of battles and people, etc., accurate. It seemed to me that the more real I made those details, the more real the magic would seem. But military history surprised me. I wasn't looking forward to researching it at all. But it's wonderful, so vivid, so immediate, so full of tiny detail. John Kincaid, a captain in the Rifle Brigade, describes in his memoirs how on the morning before Waterloo he and his men made a huge cauldron of sweet, milky tea and all the great generals from Wellington downward stopped to beg a cup. You can just picture it. Military history is an extraordinary mixture of mind-numbing horror and heartwarming detail like this. It's perfect for a novelist. Political history is a lot less satisfactory. Political historians want to understand how the prime minister, Lord Liverpool, affected the Catholic Emancipation. They're a lot less interested in whether he daydreamed about a quiet life pottering about on a boat somewhere, whether he suffered from nightmares or bad colds, whether he liked anchovies. All of which is stuff that interests me much more.

The most magical thing, in a good way, about writing a book is the way the world will sometimes just make you a little present of a fact. In Jonathan Strange & Mr Norrell, Strange becomes acquainted with Lord Byron. I discovered that shortly after the date when they are supposed to meet, Byron actually started to write a poem about a magician. That was so perfect for me, and something I had no right to expect. Byron wasn't even particularly interested in magicians as far as I'm aware.

Your book's sales are likely to be helped by the increased interest in English magic sparked by the Harry Potter series. How do you see your book in relation to Rowling's children's series?

When I began writing Jonathan Strange & Mr Norrell, I assumed I was the only grown-up person obsessed with magicians and magic. But then while I was writing, Harry Potter happened, and the world changed in a way that seemed very favorable to me. It turns out there are thousands and thousands of people who love old-fashioned narrative and who love stories about magicians. I am very grateful for that.