Roman History, Volume VII

Dio Cassius (Cassius Dio), ca. 150–235 CE, was born at Nicaea in Bithynia in Asia Minor. On the death of his father, who was the Roman governor of Cilicia, he went to Rome in 180, entered the Senate, and under the emperor Commodus became an advocate. He held high offices and became a close friend of several emperors. Dio was made governor of Pergamum and Smyrna, served as consul in 220, and was a proconsul of Africa. He also became governor of Dalmatia and then of Pannonia, and was again consul in 229.

Of the eighty books of Dio's great work, Roman History, which covers the era from the legendary landing of Aeneas in Italy to the reign of Alexander Severus (222–235 CE), we possess Books 36–60. Books 36 and 55–60 have gaps, and these cover the years 68 BCE–47 CE. The missing portions are partly supplied for the earlier gaps by Zonaras, who relies closely on Dio. For some later gaps (Book 35 onwards), coverage is provided by John Xiphilinus of the eleventh century. There are also many excerpts.

The facilities for research afforded by Dio's official duties and his own industry make him a very vital source for Roman history of the last years of the republic and the first four emperors.

The Loeb Classical Library edition of Dio Cassius is in nine volumes.