This biography investigates the life and political trajectory of Septimius Severus, the first Roman emperor of African origin, to determine how his military background and administrative reforms stabilized the empire during a period of intense civil strife. Anthony Richard Birley, a renowned scholar of Roman history, utilizes primary sources such as Cassius Dio and Herodian alongside archaeological evidence to reconstruct the emperor's rise from Leptis Magna to the imperial throne. The book argues that Severus was a pragmatic, albeit ruthless, ruler whose focus on military loyalty and legal centralization fundamentally altered the structure of the Roman state.

Historians and classicists frequently cite this work as the definitive academic biography of Septimius Severus due to its rigorous engagement with primary source material. Readers often note the scholarly density of the prose, which provides a comprehensive look at the complexities of third-century Roman governance.