Galerius

Gaius Galerius Valerius Maximianus rose through the Tetrarchy as caesar under Diocletian, fighting the empire's border wars: he defeated the Sasanian king Narseh at Satala in 298, likely sacked Ctesiphon the next year, and crushed the Carpi across the Danube in 297 and 300. When Diocletian abdicated in 305, Galerius became augustus, but the power-sharing system fractured around him as usurpers multiplied. A committed enemy of the Christian faith, he had enforced its persecution — until 311, when he issued the Edict of Serdica and called it off. He died that May.