253 Valerian proclaimed emperor; marches on Rome; recognized by the Senate after the death of Aemilianus; Sasanian invasion of Syria; Gothic naval expedition to Asia Minor; appoints Gallienus co-ruler
254 Consul (with Valerian II); Stays in the Balkans; accepts the title Germanicus
255 Consul II (with Valerian III); accepts the title Germanicus maximus
257 Consul III (with Valerian IV); accepts the title Germanicus maximus III and Germanicus maximus IV; Valerian launches persecution of the Christians; accepts the title Dacicus maximus
258 Visits the Rhineland; accepts the title Germanicus maximus V; death of Valerianus Junior
260 Valerian taken captive by Shapur; many usurpations (Macrianus, Quietus and Ballista in the east; Ingenuus and Regalianus in Pannonia); Gallienus accepts the existence of the Palmyrene Empire (Odaenathus) and Gallic Empire (Postumus); Gallienus defeats the Alamans near Milan; puts an end to the persecutions of Christians; loses his son Saloninus; Aureolus defeats Ingenuus
261 Consul IV (with Lucius Petronius Taurus Volusianus); Aureolus defeats Macrianus; Odaenathus takes Emesa and executes Quietus and Ballista; rebellion of Mussius Aemilianus; brief revolt of Piso and Valens in Thessaly
262 Consul V (with Nummius Fausinianus); arrest and execution of Mussius Aemilianus; brief revolt of Aureolus, who surrenders to Gallienus; death of Valerian, still captive; Arch of Gallienus
264 Consul VI (with Saturninus); visits Greece; initiated in the Mysteries of Eleusis; Gallienus' victory over the Sarmatians?; Regalianus killed?
265 Attacks Postumus in Gaul, unsuccessfully
266 Consul VII (with Sabinillus)
Rome, Arch of Gallienus
267 The Heruli sack Byzantium; Visigoths invade Asia Minor; Odaenathus killed, but succeeded by Vaballathus and Zenobia
268 Defeats the Visigoths and Herulians near Naissus; second revolt of Aureolus in Milan; Gallienus murdered during the siege of Milan, probably together with his wife Salonina
