Ronan Bennett's Havoc, in Its Third Year (2004) answers every qualm I've had about the genre. It's saturated with history without hitting the reader over the head with names and dates. Its plots and subplots are inextricably bound up with the historical issues at hand (religious and political strife in seventeenth-century England), so there is no tension between history and mystery.
The dialogue has the barest hint of archaism to it, light enough not to be obtrusive, but just enough to remind readers that the story's time is not their own. The protagonist, a discreetly Catholic coroner and civic official named John Brigge, is one of the most admirable characters in all of fiction, at least through the book's first two-thirds or so. There's even a murder mixed in.
I do much of my reading late at night, so I could well rate books by how late they keep me up. Havoc, in Its Third Year receives the first-ever, surely soon to be coveted 6+ rating, for keeping me up past 6 a.m.
“Indeed, sir. Many have it that the air of the fens is notorious and unclean, and the life there so uncivil that people say, to describe a fall in the world, that a man goes from the farm to the fen and from the fen to Ireland.”© Peter Rozovsky 2011