It's fantasy, but set in the Regency. Excellent book with fantastic atmospheric drawings. It's a bit of an alternate history where magical still exists but only in a theoretical form, until Mr Norrell, a reclusive old miser from Yorkshire who buys up all the books, restores it. It's used in the war effort against Napoleon (hilarious bit where he tries, unsuccesfuly, to frighten napoleon by sending him nightmares: a dragoon hiding in his closet) and he takes on a young pupil, the eccentric but charming gentleman Jonathan Strange. The two eccentrics soon become rivals. Good villain and interesting subplot about the mythical Raven King. Verry witty, with psuedo-academic footnotes. Look for Susanah Clarke's official site.