One ancient source called Severus the most warlike of all men who had lived up to that moment in time. The rise of Septimius Severus to power started the dominance of the military in Roman affairs and it was because of this that Septimius's advice for his sons was nothing less than: 'Be harmonious, enrich the soldiers, and scorn all other men!'

Ilkka Syvanne explains in detail how the African Septimius Severus achieved his position, how he won his wars and battles and how he used his newly gained power to secure his family's position. He reveals how he reformed the state and its military, and how he used these remodelled forces in wars of conquest to prove his worth as emperor to both the soldiers and the populace. This biography offers the first complete overview of the policies, events and military campaigns of Severus' reign in the fullest detail allowed by the sources. It also explains how and why these contributed to the military crisis of the third century and discusses the legacy he left for his son, Caracalla, who followed him in both his good and bad traits.