Caius Valerius Maximiauus Galerius, a Roman emperor, reigned from A. D. 305 to 311. A native of Dacia and the son of a peasant, he distinguished himself in the armies by his courage, and was appointed Caesar in 292 by Diocletian, whose daughter he married. Receiving Thrace and Macedonia for his province, he was defeated by the Persian king Narses, but was so disdainfully received by the emperor at Antioch on his return that he again set out, crossed the Euphrates, and gained a decisive victory over the Persian king. He now extorted from Diocletian an edict of proscription against Christianity, which was bloodily executed. After the abdication of Diocletian in 305 he reigned over the East; but when Italy recognized the authority of the usurper Maxentius, he marched thither to besiege Rome, which he had never yet seen, but was defeated by Maxentius (307). The rest of his life was devoted to the draining of lakes and the clearing of forests.