During the five decades since the Treaty of Rhandeia ended the War of Armenian Succession, an uneasy peace has existed between the Roman and Parthian Empires. The treaty’s terms dictated the King of Armenia must come from Parthia’s ruling Arsacid Dynasty but can only be lawfully crowned by the Emperor of Rome. Following the passing of King Sanatruk in 110 A.D., King Osroes of Parthia appoints a new Armenian sovereign with neither consultation nor consent of Emperor Trajan. Three years later, he forcibly removes the king and installs another, again without the knowledge or permission from Rome.

Trajan sees this grievous insult as recourse to settle ancient enmities dating back to Rome’s bloody humiliation at the Battle of Carrhae, 160 years prior. Parthia lies weakened by two generations of strife between rival claimants to the title, King of Kings. After seven years of peace, the legions of Rome march to war.

For Tiberius Artorius Castus, his world is changing. The end of his tenure in Mancunium sees him appointed as senior military adviser to the Governor of Britannia. Now married, and soon to be a father, Tiberius receives an esteemed honour from Emperor Trajan, an honour that will take him away from his family to the furthest end of the Roman Empire.