Dio's Roman History spans nearly a millennium, from the arrival of Aeneas in Italy until the year 229. His contemporaneous account of Elagabalus's reign is generally considered more reliable than the Augustan History or other accounts for this general time period,Maggie L. Popkin, The Architecture of the Roman Triumph (2016), p. 170: "[of] Cassius Dio, Herodian, and the Historian Augusta[,] Dio is generally considered our most reliable source for this period [the Severan era]"Martin M. Winkler, The Fall of the Roman Empire: Film and History (2012), p. 63: "Dio, a close contemporary [of Aurelius] and generally considered the most reliable source for his own time" though by his own admission Dio spent the greater part of the relevant period outside of Rome and had to rely on second-hand information.
