This is the final volume in the series of commentaries on Ammianus' Res Gestae. The last book of Ammianus Marcellinus’ Res Gestae is the most important source for a momentous event in European history: the invasion of the Goths across the Danube border into the Roman Empire and the ensuing battle of Adrianople (378 CE), in which a Roman army was annihilated and the emperor Valens lost his life. Many contemporaries were of the opinion that this defeat heralded the decline of the Empire. Ammianus is sharply critical of the way Valens and his generals handled the military situation, but holds on to his belief in the permanence of Roma Aeterna, reminding his readers of earlier crises from which the Empire had recovered and pointing to the incompetence of the barbarians in siege craft.

The first part of Book 30 of Ammianus Marcellinus’ Res Gestae is devoted to the military and diplomatic struggle for Armenia between Valens, emperor of the East, and king Sapor II of Persia. The Romans successfully defend their position, until they are forced to deal with the Goths who threaten to cross the Danube border. The second half of Book 30 is dominated by Valentinian I, emperor of the West. Ammianus presents a kaleidoscopic picture of this emperor alternating between admiration for his military qualities and devotion to his duty and bitter criticism of his avarice and cruelty. The account of his death forms the conclusion of Ammianus’ treatment of the history of the western half of the Empire.

Book 29 opens with the judicial terror in Antioch following the discovery of a plot against the emperor in the East, Valens, who played an active role in hunting down and executing the culprits. The account of these internal troubles is balanced by two long chapters at the end of the book dealing with warfare in Africa and Central Europe. The general Theodosius mercilessly crushed the revolt of the Moorish prince Firmus, while the emperor in the West, Valentinian, had to deal with violent invasions of the Quadi and the Sarmatians. The two central chapters are devoted to different aspects of Valentinian’s character, his cruelty on the one hand, his diligence in reinforcing the border defenses on the other.

Continuing the series of philological and historical commentaries on Ammianus' Res Gestae this volume deals with Book 26, in which the beginning of the reign of Valentinian and Valens is described and the rise and fall of the usurper Procopius.

Constantius II, son of Constantine the Great, ruled the Roman Empire between 337 and 361 CE. Constantius’ reign is characterised by a series of political and cultural upheavals and is rightly viewed as a time of significant change in the history of the fourth century. Constantius initially shared power with his brothers, Constantine II and Constans, but this arrangement lasted a short period of time before Constantine II was killed in a contest over authority by Constans. Further threats to the stability of the empire arose with the usurpation of the ambitious Roman general Magnentius between 350 and 353, and additional episodes of imperial instability occurred as Constantius’ relations with his junior Caesars, Gallus and Julian, deteriorated, the latter to the point where civil war would have been on the cards once again if Constantius had not died on 3 November 361. This book examines the dynastic, political and cultural impact of Constantius' reign as a member of the Constantinian family on the later empire, first as a joint ruler with his brothers and then as sole Augustus. The chapters investigate the involvement of Constantius in the imperial, administrative, legal, religious and cultural life of the Roman Empire in the fourth century. Constantius’ handling of various threats to Roman hegemony such as the ambitions of the neighbouring Sasanian Empire, and his relationships with Gallus and with Julian are explored. The book’s analysis is guided by the epigraphic, iconographic, literary and legal evidence of the Roman and Byzantine periods but it is not a conventional imperial ‘biography’. Rather, it examines the figure of Constantius in light of the numerous historiographical issues surrounding his memorialisation in the historical and literary sources, for instance as ‘Arian’ tyrant or as internecine murderer. The over-arching aim is to investigate power in the post-Constantine period, and the way in which imperial and episcopal networks related to one another with the ambition of participating in the exercise of power. The Reign of Constantius II will appeal to those interested in the Later Roman Empire, the Constantinian imperial family, Roman-Sasanian relations, and the role of religion in shaping imperial dynamics with Christianity.

Continuing the series of philological and historical commentaries on Ammianus' Res Gestae this volume deals with Book 28, which is devoted primarily to the deplorable events in Rome during the reign of Valentinian and his defense of the Rhine frontier.