Diocletian, Roman emperor from 284 to 308, born at Salona, in Dalmatia, of obscure parentage; having entered the Roman army, served with distinction, rose rapidly to the highest rank, and was at Chalcedon, after the death of Numerianus, invested by the troops with the imperial purple; in 286 he associated Maximianus with himself as joint-emperor, with the title of Augustus, and in 292 resigned the Empire of the West to Constantius Chlorus and Galerius, so that the Roman world was divided between two emperors in the E. and two in the W.; in 303, at the instance of Galerius, he commenced and carried on a fierce persecution of the Christians, the tenth and fiercest; but in 305, weary of ruling, he abdicated and retired to Salona, where he spent his remaining eight years in rustic simplicity of life, cultivating his garden; bating his persecution of the Christians, he ruled the Roman world wisely and well (245-313).