Themistius and Valens offers the first complete English translation and analysis of Themistius' speeches for or on behalf of the emperor Valens (r. 364-378). As a westerner and a Latin speaker, Valens had a tough job to convince the aristocracies of Constantinople and the East that he shared their expectations and knew how to preserve their wealth and security. By 364 Themistius already enjoyed huge influence. He was famous as a philosopher who was 'an exceptional citizen', and his leadership of the dramatic expansion of the senate in 359 gave him the best address book in town. His ambition and political sense made him a perfect ally for communicating imperial policy and action. These speeches present the major issues Valens faced: his right to rule alongside the western emperor, his brother Valentinian, his handling of the revolt of Procopius, his ability to manage the empire's economy and borders, his wars against the Goths and the Persians, his controversial religious and judicial policies, and the clever diplomatic work Themistius undertook for him in the lead up to his death in battle in 378.