Septimius Severus was from [Leptis Magna]? (in modern Libya) and owed his advancement to [Aemilius Laetus]? who was the last [praetorian prefect]? of Commodus?. Severus claimed the throne in April 193 and prepared to fight [Didius Julianus]? but the legions? of Julianus refused to fight and Severus was proclaimed emperor. It was not until 197 that all competing claimants were eliminated.
In the later years of his reign Severus undertook a number of military actions in defence of Roman Britain against barbarian incursions and undertook reconstruction of Hadrian's Wall before dying in York on the 4th February AD 211.
See also Roman Empire, Roman Emperors, Byzantine Empire and Byzantine Emperors.