200–c. 260s
Valerian ruled the Roman Empire from AD 253 to 260 during a period of invasion, plague and internal instability. He appointed his son Gallienus as co-emperor and campaigned in the east against the Sasanian king Shapur I.
Defeated near Edessa, Valerian was captured alive, an unprecedented humiliation for a reigning Roman emperor, and his later fate is uncertain. Valerian held the title of Roman emperor and ancient Roman senator.
Valerio Massimo Manfredi’s Empire of Dragons begins with Valerian’s capture after Edessa and follows members of his defeated guard into Persian captivity. Harry Sidebottom’s King of Kings portrays the fragile joint rule of Valerian and Gallienus as civil war and the Sasanian threat pull the empire apart, while Lion of the Sun opens with Valerian’s army collapsing and the emperor falling into Shapur I’s hands. Nick Holmes’ The Roman Revolution uses that capture as a defining moment in the third-century crisis, linking it to breakaway empires and the later recovery under Aurelian. Ian Hughes’ Thirteen Roman Defeats places Edessa within a longer study of Roman military disasters and the strategic changes forced by defeat.