296 CE

Pope Caius dies after a 13-year reign and is succeeded by Marcellinus as the 29th pope of Rome. The Persian king Narseh invades Roman-held Upper Mesopotamia and Arsacid western Armenia, the latter territory being under the leadership of the pro-Roman king Tiridates III. With only a small army, Caesar Galerius fights three holding actions against Narseh's army in Mesopotamia. Somewhere in the open plains between Carrhae and Callinicum, Galerius' army suffers a defeat against the Persian army, which is both more numerous and contains superior numbers of high-quality cavalry. Nevertheless, Galerius succeeds in blunting the Persian offensive. In this or the previous year, Caesar Constantius I assembles two invasion fleets with the intent of overthrowing the usurper Allectus, who is based in Britain. The first is under the command of Asclepiodotus, Maximian's long-serving Praetorian Prefect. Asclepiodotus sails from the mouth of the Seine, and lands near the Isle of Wight, where his forces defeat Allectus in Hampshire. Allectus is killed in the fighting. Constantius leaves Boulogne with his fleet, and occupies London, where he slaughters some of Allectus' Frankish mercenaries. With this victory, the Romano-British regime first established by Carausius is overthrown, and Britain is re-incorporated into the rest of the empire.

In the 290s, the 3rd century.