Cassius Dio

Cassius Dio (Lucius Cassius Dio Cocceianus, c. AD 155–235) was a Roman senator of Greek speech, born at Nicaea in Bithynia, the son of a senator who governed Cilicia and Dalmatia. He came to Rome as a young man, entered the Senate under Commodus and was praetor under Pertinax. He later governed Pergamum and Smyrna, then Africa, Dalmatia and Upper Pannonia, and held the consulship twice, the second time in AD 229 as colleague of the emperor Severus Alexander.

He served close to the court of the Severan emperors and saw Caracalla and Macrinus at close hand. His great work, the Roman History, was written in Greek in eighty books and ran from the legendary landing of Aeneas in Italy to AD 229, the year of his second consulship. He spent about twenty-two years on its composition.

Only Books 36–60 survive entire; the earlier books are known from the epitome of the Byzantine chronicler Zonaras, and later ones from Xiphilinus and scattered fragments. This archive carries the first volume of Herbert Baldwin Foster's English version (1905), which renders the lost early books as they come down in Zonaras and the fragments.