Valens Thessalonicus

Valens Thessalonicus was a Roman usurper active in Achaea during the reign of Emperor Gallienus in the mid-3rd century. He was proclaimed emperor by his troops in 261 CE during the period of political and military turmoil known as the Crisis of the Third Century. Valens's brief revolt occurred while Gallienus faced a series of simultaneous uprisings across the empire following the capture of his father, Emperor Valerian, by the Persian king Shapur I.

Almost all information about Valens comes from later literary sources, which provide fragmentary and uncertain accounts. He appears to have served as governor of Achaea and was targeted by forces loyal to the eastern usurper Macrianus Major, who sought to secure his line of advance westward. When the general Piso was sent to eliminate him, Valens's own troops turned on Piso and killed him. Shortly afterward, Valens himself was murdered by his soldiers for reasons unknown. His brief reign illustrates the instability of imperial power during the 260s, when numerous commanders were elevated by their troops and swiftly overthrown.