Dio Cassius, too often consulted just as a historical source, was an historian of considerable interest and originality at once a Greek man of letters and a late representative of the Roman tradition of senatorial historical writing. For the reign of Augustus his history is much the fullest account to survive. This edition covers the years 28 to 5 BC, after which there are substantial gaps in Dio’s text; it includes Dio’s extended discussion of the constitutional settlement of 27 BC and the imperial system it inaugurated. The notes discuss the historical subject matter and Dio’s treatment of it; particular attention is paid to the way Dio shaped his material in the light of his own values and interests. The introduction deals with Dio’s life, the character of his history, and his view of Augustus.