Pashazade - Jon Courtenay Grimwood
I've read standalone novels by Grimwood before but never been able to get hold of this, the first of his Arabesk trilogy of books.

The protagonist in Pashazade is Ashraf, recently returned to Alexandria and replete with all the trappings of a rich man's son in a world where the Ottoman empire never fell. The problem is, Ashraf is a phoney, more at home in the American prison he recently left than dealing with the hierarchical society of Egypt and a potential arranged marriage to a girl who's equally unimpressed with the idea.

The alternate history is well thought out, as is the world-building, and though Ashraf is quite ruthless at times, he's also a sympathetic character who is out of his depth and knows it. I'm not really sure where the rest of the trilogy is going to take these characters, but I'm looking forward to it - the next book in the series is Effendi.