Roman emperor. Born in 146 in Leptis Magna, Africa; died in York, England in 211. Legate of the fourth legion on the Euphrates and later governor of Upper Pannonia. Proclaimed emperor by the Danube legions in 193. At the battle near Lyons in 197, he conquered his rival Albinus. Severus labored to reorganize the Empire on the model of an Oriental despotism, and favored the provinces rather than Italy, basing his power on the Pretorian Guard. The fifth persecution of the Chtistians broke out during his reign.