Ovid's Fasti has remained curiously neglected as an historical source for the period in which it was written. This new study reveals that the poem of some five thousand lines on the Roman calendar, written and revised in the years between A.D. 4-16, provides students of the Augustan age with a wealth of information, both about the author himself, and about his cultural and political environment. In addition to revelations about the way in which Augustus and his family were incorporated into the ancient religion of the city of Rome, and details of the last decade of Augustus' life and the first years of Tiberius' rule, Herbert-Brown finds in the poem new evidence of the processes which marked the transition from the Republic to Empire.