For this Fortnightly Book, I've decided to do Susanna Clarke's Jonathan Strange & Mr Norrell; given the size of the book and the time of year, this might end up being one of those three week fortnights.
Susanna Clarke worked on the novel for ten years, publishing a short story here and there. For her day job she edited cookbooks. The basic idea for an ambitious book of fantasy was inspired by Tolkien, but the content was based on a dream she had about a man, dressed as if in the eighteenth century, in Venice, with some sort of magical doom hanging around him. (The last time I read this, I remember the Venice episode seeming like a mildly interesting but not especially important digression; but discovering that this was the seed of the book puts it in a different perspective.) She did not, however, ever plan on the book taking ten years; in interviews she's said she kept expecting to finish it the next year, and would not have begun it if she had known it would take so long. One reason she could think of such a big project as being completable in just another year is that she wrote the whole thing in fragments, a little here, a little there, and wove them together, and discovered as she did so that she need something about this, something about that, and she kept going until it fit together fairly well.
We begin in the year 1806; England is faring badly in the Napoleonic Wars. And in Yorkshire a reclusive man named Gilbert Norrell is about to restore English magic; he will soon be joined by an opposite counterpart, Jonathan Strange. And together they are going to find that this involves more than they bargained for. It's in many ways a very dark story, although I think it is prevented from being unbearably so by the spirit of the times it depicts -- the Englishness of the time depicted, for all its social failings and moral ambiguities, resists any outright nihilism.