Galerius

Gaius Galerius Valerius Maximianus (; Greek: Γαλέριος; c. 258 – May 311) was Roman emperor from 305 to 311. He participated in the system of government later known as the Tetrarchy, first acting as caesar under Emperor Diocletian. In this period Galerius obtained victory warring against the Persian Sasanian Empire, defeating Narseh at the battle of Satala in 298 and possibly sacking the Sasanian capital of Ctesiphon in 299. He also campaigned across the Danube against the Carpi, defeating them in 297 and 300. Galerius was promoted to augustus upon the abdication of Diocletian in 305, but had to contend with multiple usurpers as the Tetrarchic system broke down. Although he was a staunch opponent of Christianity, he ended the Diocletianic Persecution by issuing the Edict of Serdica in 311.