The New International Encyclopædia/Dio Cassius Cocceianus

​DI′O CAS′SIUS COC′CEIA′NUS (Gk. Δίων Κάσσιος Κοκκηιανός, Diōn Kassios Kokkēianos) (c.150–235). A celebrated Greek historian. He was born at Nicæa, in Bithynia. He held various high offices of State under the Roman emperors, was twice consul, and enjoyed the intimate friendship of the Emperor Alexander Severus. He is best known by his History of Rome, in eighty books, from the arrival of Æneas in Italy to A.D. 229, of which only twenty-four (36–60, covering the years B.C. 68 to A.D. 47) have reached us fairly complete. The others are known to us only from fragments and the abridgment made by Xiphilinus in the eleventh century. Dio’s high position gave him free access to the national archives, and as an authority on some points—especially on the imperial epoch of Roman history—his work is of considerable value. He wrote on the model of Thucydides, to whom, indeed, he is far inferior, both in vigor of judgment and acuteness of criticism; yet many passages of his History might be quoted as among the best samples of the rhetoric of the age in which he lived. Dio died at Nicæa, about A.D. 235. The History is best edited by Boissevain (Berlin, 1895–1901).