Brother Cadfael’s Penance, by Ellis Peters

Oddly, this isn’t so much a mystery as it is a historical novel pure and
simple. Sure, there’s a murder…but what there really is, is a
complicated political setup involving a civil war, some poignant family
connections across the battle lines, and some of Cadfael’s own past
history. It turns out to be quite a good book, but the initial set up is
brutally long, about fifty or so pages, before you can even understand
who the players are. I suppose more of them would have been familiar if
I’d been reading the series in sequence. Anyway, recommended–but don’t
think it’s a typical Brother Cadfael mystery.