Lucius Cassius Dio Cocceianus (c. 150 – 235 CE, known in English as Cassius Dio, Dio Cassius, or Dio (Dione.

lib) is a Roman consul and a noted historian writing in Greek.

Dio publishes a history of Rome in 80 volumes, beginning with the legendary arrival of Aeneas in Italy through the subsequent founding of Rome (753 BCE), the formation of the Republic (509 BCE), and the creation of the Empire (31 BCE), up to 229 CE; a period of about 1,400 years.

Of the 80 books, written over 22 years, many survive into the modern age intact or as fragments, providing modern scholars with a detailed perspective on Roman history.