This book is the first history of civil war in the later Roman Empire to be written in English. It advances the thesis that civil war was endemic to the later Empire (third to fifth centuries AD) and explores the way in which successive imperial dynasties—many of whose founding members had themselves usurped power—attempted to legitimate themselves and counter the threat of almost perpetual internal challenge to their rule. The work takes as its operating principle that history is written by the victors, and seeks to employ panegyric as a tool to understand the processes that, according to one contemporary commentator, ‘made tyrants by the victory of others’. Panegyric provides direct evidence of how, in the wake of civil wars, emperors attempted to publish their legitimacy and to delegitimize their enemies. The book explores the ceremony and oratory that surrounded imperial courts, examines how and why this ceremony was aggressively used to dramatize and constantly recall the events of recent civil wars, and, above all, it explores how the narratives produced by the court in this context went on to have enormous influence on the messages and narratives found within contemporary historical texts. The resulting book is a thoroughly original reworking of late Roman domestic politics, an exploration of the way that successive imperial courts sought to communicate with their subjects, and an examination of the fallibility of history.

This chapter sets out the aim of this book to explore civil war through the medium of the panegyrical corpus, and justifies this potentially controversial decision. The corpus of forty-eight speeches is defined and the book sets out its unprecedented programme to draw upon all speeches and authors within the period of the late third and fourth centuries AD, uniting a vast body of evidence that is usually compartmentalized in individual studies. The chapter then explores the extent to which panegyric, as a genre, concerns itself with themes of usurpation and civil war, and explores how the polemic directed against the emperor’s enemies can be used to understand the processes by which the reputations of defeated parities in civil war were blackened.

Damnatio memoriae, the ill-defined group of processes that we often now refer to by the term ‘memory sanctions’, is generally thought of in wholly negative terms. It is imagined as a process of destruction, of erasure, and of silence. Yet these complex assaults on the memory of fallen enemies were far more than simply destructive processes. Through the example of Magnus Maximus (383–8) and his commemoration in Rome and Constantinople during the reign of Theodosius I, this article considers how memory sanctions could be generative of historical material and how emperors used oratory, ceremony and triumphal architecture to memorialise their fallen enemies.

This chapter examines three moments of political crisis during the period 337‒54. First, the chapter defends the notion that the so-called ‘great massacre’ of 337was orchestrated by, or with the connivance of, Constantius. It then considers the wars between the sons of Constantine in the 330s and 340s. It contrasts the bitter antipathy between Constantius and Constans with the rhetoric of fraternal harmony in Libanius’ Oratio LIX. Finally, the chapter examines the death of Constans, the usurpations of Magnentius and Vetranio, and Constantius’ war in the West from 350‒3. The chapter explores how Julian’s Orationes I and II and Themistius’ Orationes II, III, and IV produced a coherent caricature of Magnentius, and also how they can be used to demonstrate that Vetranio’s usurpation in Illyricum was in defence of Constantius, and that Vetranio willingly laid down power in 350. The chapter also contains some remarks on the usurpation of Silvanus.

This short chapter constitutes an introduction to the main body of the work, and sets out the wide-reaching consequences of permanent civil war within the later Roman Empire. It argues that previous research has overemphasized the importance of external warfare with the barbarian outsiders in recounting the political and military history of the late third and early fourth centuries. Far more important were the wars that Romans fought against themselves. The chapter sets out the broadly chronological structure of the book, and urges the reader to see that chapter divisions organized by dynasty should not suggest that this book takes a traditional approach to late Roman history. Far from it: the legitimacy of many of the late Empire’s great dynasties will be thrown open to question.