Caesar Ascending-Conquest of Parthia

Caesar Ascending-Conquest of Parthia, is the second volume of the alternate history series in which Caesar survives the assassination attempt in March of 44 BC and carries out his planned invasion of Parthia. After a successful first year's campaign, where Caesar and his army capture the cities of Ctesiphon and Seleucia, Caesar is now determined to face and defeat the young Parthian king Phraates, who is just as intent on avoiding battle with the Roman general.
For Titus Pullus, the giant Primus Pilus of the 10th Legion, and his comrades, matters are further complicated by the presence of a force called the Crassoi, the Roman survivors of the ill-fated campaign led by Marcus Crassus, who are now fighting for Parthia. What neither Caesar, nor any Roman, has any way of knowing is whether their former countrymen still hold any loyalty to Rome, or if the decade they have spent under Parthian control has been enough to switch their allegiance to their captors.
All will be decided outside the walls of Susa, when Caesar and his army must not only once more face the feared Parthian cavalry, but fellow Romans.