DIONE CASSIUS (Δίων ὁ Κάσσιος). — Historian, born in Nicaea c. AD 155, died there nearly eighty years old between AD 230 and 240. He began his political career in Rome. He was proconsul of Africa and twice consul. He wrote in Greek, in 80 books, a History of Rome (Παμαχὴ Ἱστορία) from Aeneas to AD 229. Only 25 books survive (from XXXVI to LX), covering the period from 68 BC to AD 47, along with various fragments, the most important of which contains Books LXXVIII–LXXIX covering AD 216–219. His narrative is arranged in an analytical order, is broad and diligent, but does not offer a new reconsideration of Roman history; he is especially interested in the civil organization of the city and shows little sensitivity to spiritual phenomena. Christianity is absent from his purview, even though he lived at the time of Marcus Aurelius and the Severans, to whose era Books LXXVIII and LXXIX refer.
Two pieces of information, however, are reported in his work: the condemnation of the consul Flavius Clemens and his wife Flavia Domitilla, respectively to death and relegation to the island of Pandataria, as guilty of impiety toward the gods (i.e., of Christianity); and that of Acilius Glabrio (Hist. Rom., LXVII, 14). Nor should the episode of the thunderstruck legion be forgotten, preserved in the Excerpta of Sifilinus (71, 8) and narrated also by Tertullian (Ad Scap., 4) and Eusebius (Hist. eccl., V, 5, 2–6).
Summaries of his work were made by Byzantine historians, especially by Sifilinus (11th century) and Zonaras (14th century), for whom, as for other Byzantine chroniclers, D. C. is the principal text of Roman history.