Revelation.  By C.J. Sansom

Series mystery.  Detective Matthew Shardlake. Set in 1543 London.

The narrator and detective of this series is Matthew Shardlake, a barrister who has been appointed to be the equivelent of Legal Aid - free legal council for the poor.  When his good friend, and the man who married the woman he loved, is murdered and his body is left on display,  Shardlake promises the widow he will find the killer.  

Historical mysteries are hard to pull off.  Often the author seems to decide "my readers wouldn't identify with someone who thinks so differently than they do, so I'll just give them contemporary attitudes in an historical setting."  As a result, they write what I call "Valley Girl Victoriana".  This drives a portion of the potential audience,  those who know and care about history, absolutely insane - and away from the series.  Sansome is liberal for his times,  but he's not Dennis Kucinich in a doublet.  

 It's also hard to accurately describe the surroundings of, say, the 15th century, without causing sensitive readers to recoil in terminal disgust. Prior to the 1900's, most streets were instep-deep in animal dung, your dinner might be killed and gutted in your front yard, and cruelty was next thing to a public sport.   
 
It's difficult to pull off well - but C.J. Sansom does it.  There is enough description of the surroundings to give the reader the right idea, and the description of the emotional climate of the times seems accurate from what I've read too.

Recommended.