True Successor: A Novel of the New Roman Empire - Tapa blanda

It is 1812 in Sapoda, a small crossroads town nestled in the neutral zone between the New Roman  and Mongol Empires.  Mikail de Reuter, a young political officer bored by his job and worried about his prospects, is only there to visit his girl. But Mongol cavalry looking to clear a path for an invasion come to kill him. He knows he has been betrayed and runs for his life.
In New Rome Emperor Charles Martel IV has had to contend with many enemies just to keep Charlemagne’s crown on his head—and that head on his shoulders. So far he has managed to hold things together. In Mikail’s story he glimpses an enormous treasonable conspiracy years in building. As the Emperor begins a  frantic hunt for them, the conspirators realize that unless they strike first they will soon be dead.
True Successor is a fast-moving good read and a trip to a fascinating New Rome for Alternate History buffs.  Like Mikail we live briefly in that city and meet and hear not  only the great men of the realm, but young lovers, clerks, soldiers and ordinary men and women shopping, drinking in its taverns and walking its streets.