253 CE - 260 CE: Reign of Roman emperor Valerian with his son Gallienus as co-emperor.

253 CE - 268 CE: Reign of Gallienus in Rome.

256 CE: King Chrocus of the Alemanni invades Gaul and destroys the region.

259 CE: The Alemanni invade Italy.

260 CE: Shapur I captures the Roman emperor Valerian at Edessa.

262 CE - 266 CE: Odaenathus expels Persian garrisons and restores Syria and Armenia to the Roman Empire. Odaenathus invades Mesopotamia, and inflicts two defeats upon Shapur I, which ends with the sack of Ctesiphon.

265 CE: Gallienus builds walls around Verona.

266 CE - 267 CE: Odaenthus is assassinated.

267 CE: Zenobia rules as Regent in Palmyra.

268 CE: Gallienus defeats Aureolus at Mediolanum.