Of peasant stock, was born in the ad 250s on the Danube. A herdsman, tough and uneducated, he rose high in the army and (perhaps) became praetorian prefect of Diocletian, to whom his loyalty was unswerving. On the establishment of the tetrarchy Diocletian proclaimed him Caesar (293); he divorced his wife and married Diocletian's daughter. Defending the frontier with Persia, he was severely defeated in 297, but raising reinforcements from the Balkans he attacked through Armenia, marched down the Tigris, and returned up the Euphrates, gaining total victory (298). The peace treaty was entirely favourable to Rome: substantial territory was annexed. Thereafter he moved to the Danube provinces. Various campaigns against the Marcomanni, Carpi, and Sarmatians followed; he settled many Sarmatians within the empire. His religious views coincided with those of Diocletian. He urged Diocletian to begin the persecution of Christians at Nicomedia (303). On Diocletian's abdication, Galerius became Augustus (305); his subordination to Constantius I meant little, as both Caesars were his men. Senior Augustus from Constantius' death (306), he reluctantly accepted Constantine I as Caesar. Summoning Diocletian after a troubled period, he attempted a new settlement of the empire at Carnuntum (308), but Diocletian refused to resume the throne. Suffering from an agonizing illness, Galerius issued an edict ending the Christian persecution (311) but died very shortly afterwards.
Subjects: Classical Studies.