Galerius

Galerius rose from herding cattle to rule the Roman east, ran the worst persecution of Christians, and ended it himself. Born around AD 258 near Serdica in Dacia Ripensis to a peasant family, he served in the ranks under Aurelian and Probus and rose through the army entirely on merit. Diocletian made him Caesar in 293, part of the four-man Tetrarchy, and required him to divorce his wife and marry Diocletian's daughter Valeria. He was defeated by the Persians near Carrhae in 296 and, according to Eutropius, was made to walk in his purple robes for a mile beside Diocletian's carriage in front of the army. He returned the following year with a force raised in the Danube provinces, caught Narseh's army unprepared in Armenia, captured the Persian king's harem and treasury, and imposed the Treaty of Nisibis — the most favourable settlement Rome ever obtained in the east, holding for forty years. That victory made him the dominant figure of the Tetrarchy, and the Christian sources, Lactantius above all, hold him primarily responsible for pressing Diocletian into the Great Persecution from 303: churches demolished, scriptures burned, clergy imprisoned, and sacrifice required on pain of death. He became senior Augustus in 305 when Diocletian abdicated, and attempted to control the succession, which produced civil war and the rise of Constantine. In April 311, dying of a disease Lactantius describes with relish, he issued the Edict of Serdica from Nicomedia, admitting that the policy had failed and granting Christians toleration. He died days later. His successors reversed nothing, and Constantine went further two years later.

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