What happened 253 AD

Since the army was no longer pleased with the Emperor, the soldiers proclaimed Aemilianus emperor. With a usurper, supported by Pauloctus, threatening the throne, Gallus prepared for a fight. He recalled several legions and ordered reinforcements to return to Rome from Gaul under the command of the future emperor Publius Licinius Valerianus. Despite these dispositions, Aemilianus marched onto Italy ready to fight for his claim and caught Gallus at Interamna (modern Terni) before the arrival of Valerianus. What exactly happened is not clear. Later sources claim that after an initial defeat, Gallus and Volusianus were murdered by their own troops; or Gallus did not have the chance to face Aemilianus at all because his army went over to the usurper. In any case, both Gallus and Volusianus were killed in August 253.

Aemilian continued towards Rome. The Roman senate, after a short opposition, decided to recognize him as emperor. According to some sources, Aemilian then wrote to the Senate, promising to fight for the Empire in Thrace and against Persia and to relinquish his power to the Senate, of which he considered himself a general.

Valerian, governor of the Rhine provinces, was on his way south with an army which, according to Zosimus, had been called in as reinforcement by Gallus. But modern historians believe this army, possibly mobilized for an incumbent campaign in the East, moved only after Gallus' death to support Valerian's bid for power. Emperor Aemilian's men, fearful of civil war and Valerian's larger force, mutinied. They killed Aemilian at Spoletium or at the Sanguinarium bridge, between Oriculum and Narnia (halfway between Spoletium and Rome), and recognized Valerian as the new emperor.

Valerian's first act as emperor on October 22, 253, was to appoint his son Gallienus caesar. Early in his reign, affairs in Europe went from bad to worse, and the whole West fell into disorder. In the East, Antioch had fallen into the hands of a Sassanid vassal and Armenia was occupied by Shapur I (Sapor).

On the Danube, Scythian tribes were once again on the loose, despite the peace treaty signed in 251. They invaded Asia Minor by sea, burned the great Temple of Artemis at Ephesus, and returned home with the plunder. Lower Moesia was also invaded in early 253. Aemilianus, governor of Moesia Superior and Pannonia, took the initiative and defeated the invaders.