“ DIO CASSIUS (more correctly Cassius Dio) , Cocceianus (c. A.D. 150–235) , Roman historian, was born at Nicaea in Bithynia. His father was Cassius Apronianus, governor of Dalmatia and Cilicia under Marcus Aurelius, and on his mother’s side he was the grandson of Dio Chrysostom, who had assumed the surname of Cocceianus in honour of his patron the emperor Cocceius Nerva. After his father’s death, Dio Cassius left Cilicia for Rome (180) and became a member of the senate. During the reign of Commodus, Dio practised as an advocate at the Roman bar, and held the offices of aedile and quaestor. ”

“ His style, though marred by Latinisms, is clearer than that of his model Thucydides, and his narrative shows the hand of the practised soldier and politician; the language is correct and free from affectation. But he displays a superstitious regard for miracles and prophecies; he has nothing to say against the arbitrary acts of the emperors, which he seems to take as a matter of course ”

“ He was raised a second time to the consulship by Alexander Severus, in 229; but on the plea of ill health soon afterwards retired to Nicaea, where he died. Before writing his history of Rome (Ῥωμαικά or Ῥωμαικὴ Ἱστορία) , Dio Cassius had dedicated to the emperor Severus an account of various dreams and prodigies which had presaged his elevation to the throne (perhaps the Ἐνόδια attributed to Dio by Suidas) , and had also written a biography of his fellow-countryman Arrian. ”