Usurper. The Parthian Chronicles, #7

Doting father? Man of peace? These things are not you, Pacorus. Have you not heard of the hydra? Cut off one of its heads and two more will replace it. You defeat one enemy and another springs forth to torment you, just as the gods torment you with endless strife. After the defeat of Mark Antony Pacorus has returned to the city of Dura to prepare for a happier campaign: the wedding of his daughter to a prince of a kingdom on the eastern frontier of the Parthian Empire.
Pacorus and his family and friends travel to the east to attend the wedding of Princess Isabella, but old scores need to be settled and a new power is rising beyond the Indus that will threaten the empire itself. Can Pacorus and the surviving Companions can save the empire and the reign of the young, duplicitous king of kings from the barbarian hordes in the east?'Usurper' followers on from 'Sons of the Citadel'.