Lucius Septimius Severus (146-211) was a Roman emperor. His reign is notable for the militarization of the government, growing Oriental influences in society, and high development of civil law.

Severus was an African from Leptis Magna. He rose through the regular course of Roman offices, was consul in 190, and was serving as governor of Upper Pannonia in 193, when Emperor Pertinax was murdered by the praetorian guard. Severus's command of 12 legions and proximity to Rome made him a favored contender for the throne. He appeared in Rome as the dead emperor's avenger and won the senators' approval by promising them respectful treatment, by disbanding the praetorian guard, which he replaced with elite from the legions, and by naming his Western rival, Albinus, his caesar (successor-designate).

After defeating his more formidable rival, Pescennius Niger, in 194, Severus started a successful campaign against the Parthians. But fear of the activities of Albinus...