A comprehensive chronicle from Aeneas to Alexander Severus. Dio Cassius (Dio of Cassius), around 150–235 AD, was born in Nicaea of Bithynia in Asia Minor. After the death of his father (a Roman governor of Cilicia), he went to Rome in 180, entered the Senate, and under Emperor Commodus was a defender. He held high offices and became a close friend of many emperors. He became governor of Pergamon and Smyrna, as well as consul in 220, overseeing Africa, governor of Dalmatia, and later Pannonia, and consul again in 229. Of the eighty books of his great work, "Roman History," which covers the period from the legendary colonization of Aeneas in Italy to the reign of Alexander Severus (222–235 AD), we have Books 36–60 (Books 36 and 55–60 have gaps), which cover the years 68 BC–47 AD. The gaps are partially filled by Zonaras, who closely relies on Dio, and for some other empty periods (from Book 35 onward) by John Xiphilinus (of the eleventh century). There are also many excerpts. The opportunities for research provided by Dio's official duties and his own work make him a valuable source for the 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.