This was historical fiction done right: set in an insane asylum in Epping Forest, swirl of thoughts and actions/reactions are almost nonlinear, and the history doesn't matter. The asylum is real, as are some of the characters, but it's not really about them and what they did as much as it's about their inner lives... mostly.

The peasant poet, John Clare, has been locked away (although the asylum is rather interesting, and several inmates are given keys so they can leave at will... as long as they come back each night). His delusions are that he is (occasionally) Lord Byron or a boxer, and his "wife" Mary was someone to whom he was never married. He's the hinge for much of the non-action, and we meet others through his eyes. Also at the asylum is Septimus Tennyson, brother of Alfred (himself given to "melancholy"). The ways in which the different inmates are treated is very much in keeping with Victorian era care (remember, this is also when the OED was being created with the help of Dr. W.C. Minor).

The encroachment of technology also plays a role, and our Head Asylum Keeper, Matthew Allen (a real person) loses interest in his inmates in order to pursue mechanical production of wooden furniture. I kid you not!

Why this book was not publicized more in the US is beyond me - it deservedly made the Booker shortlist. If you can find a copy, read it.