Political map of Europe & the Mediterranean 24 April 166 (Lucius Verus’ Parthian War): Lucius Verus traveled to Syria to deal with the Parthian threat in 162, but left the conduct of the war entirely in the hands of his generals. Roman forces retook Armenia the next year then, after a fight over Osroene, invaded the Parthian Empire itself in 165 (Roman–Parthian War of 161–166). Despite sacking the capital Ctesiphon and even advancing into Media (Media (region)), the Roman campaign was called off in mid-166 following the outbreak of plague among the legions (Antonine Plague).