My latest reading has been The Snake Stone by Jason Goodwin. I am not normally a reader of crime fiction but this book is set in Istanbul 1838. The author is an historian who has written a very readable history of the Ottoman Empire, Lords of the Horizon. It is the second book in this series. I have read The Janissary Tree and would recommend that as well.
The main character and detective is Yashim the Enuch. I won't spoil the story other than to say it involves Byzantine treasure and several murders. The author really knows his way around 19th Century Istanbul and weaves in the sights and the polyglot peoples of this wonderful city. Lots of Balkan interest here both Ottoman and Byzantine and the Gallipoli battlefields are a reasonable drive away.