In Diodorus Siculus and the World of the Late Roman Republic Charles E. Muntz offers a fresh look at one of the most neglected historians of the ancient world and recovers Diodorus' originality and importance as a witness to one of the most tumultuous periods in antiquity. Muntz analyzes the first three books of Diodorus, which cover "barbarian" ethnography, myth, and early history and contain the most varied and eclectic material in his work. He shows how Diodorus defines the physical, political, and cultural boundaries of the late Roman Republic in these books and uses them to map out future possibilities for the Romans. Diodorus reveals through the history, myths, and customs of the "barbarians" the secrets of successful states and rulers, and contributes to the debates surrounding the transition from Republic to Empire. Muntz establishes just how linked the "barbarians" of the Bibliotheke are to the crumbling Republic and demonstrates that through the medium of the ancient Egyptians, Assyrians, Indians, and others Diodorus engages with major issues and intellectual disputes of his time, including the origins of civilization, the propriety of ruler-cult, the benefits of monarchy, and the relationship of myth and history. Diodorus has many similarities with other authors writing on these topics, including Cicero, Lucretius, Varro, Sallust, and Livy. But, as Muntz argues, engaging with such controversial issues, even indirectly, could be dangerous for a Greek provincial such as Diodorus, and he may never have completed or fully published the Bibliotheke in his lifetime.