Harry Turtledove 
Videssos Besieged 

With the arrival of spring, the Emperor Maniakes vows to unleash his battle-hardened troops against the enemy capital, where a hated despot sits arrogantly upon the throne.But from the moment Maniakes reaches the land of the Thousand Cities, he is plagued by a question no one can answer. Where is his nemesis, the ruthless commander whose cavalry no opposing force can withstand? The answer is cataclysmic. In a bold tactical stroke, the enemy general has thrown his bloodthirsty army against the very gates of Videssos itself.Now besieger becomes besieged, as Maniakes struggles to avert total catastrophe…