[18] This was a marked departure from the constitutionalism of his immediate predecessors, Tacitus and Probus, who at least outwardly respected the authority of the senate, and was the precursor to the even more despotic military autocracy of Diocletian.

[20] Carus then proceeded through Thrace and Asia Minor, annexed Mesopotamia, pressed on to Seleucia and Ctesiphon, and marched his soldiers beyond the Tigris.

[22][28] The Sassanid King Bahram II, limited by internal opposition and his troops occupied with a campaign in modern-day Afghanistan, could not effectively defend his territory.

[29] Rome's hopes of further conquest, however, were cut short by his death; Carus died in Sasanian territory, probably of unnatural causes, as he was reportedly struck by lightning.

[31] The report of the lightning strike was evidently widely accepted in the camp, and the superstitious awe of the troops inclined them to ascribe Carus' death to the wrath of the Gods.

Rumors had been spread of dark oracles, affixing the limits of the Empire on the Tigris, and threatening destruction against the Roman who should presume beyond the river in arms.

Persia was abandoned to her rightful possessors, and not till Diocletian, a decade later, was the Persian contest decided in Rome's favor, by that emperor's decisive victory.

In the sphere of civil affairs, Carus is remembered principally for the final suppression of the authority of the senate, which had been partially restored under Tacitus and Probus.