Lucius Cassius Dio, also known as Dio Cassius, was a Roman historian and senator of maternal Greek origin. He published 80 volumes of the history of ancient Rome, beginning with the arrival of Aeneas in Italy. The volumes documented the subsequent founding of Rome, the formation of the Republic, and the creation of the Empire up until 229 AD, during the reign of Severus Alexander. Written in Koine Greek over 22 years, Dio's work covers approximately 1,000 years of history.