The eastern frontier of the Roman Empire with special reference to the reign of Constantius II

The basic intention of the thesis is to provide a reassessment of Constantius as a military man, specifically in the prolonged war with the Sassanian king, Sapor II. However, it also encompasses many aspects of the social, economic and religious life of the communities which lay on the frontier between Rome and Persia. In the first chapter I discuss the historical background upto the death of Constantine, attributing the major reorganization of the eastern limes to the time of Diocletian and Galerius. In chapter II I describe events on the frontier during Constantius 1 reign. I adduce reasons for his adoption of a defensive strategy against the Persians and consider the nature of the Roman forces and fortifications in northern Mesopotamia. Chapter III contains a survey of the frontier legions and the major centres which they defended. In the fourth chapter an analysis of Persian aims and capabilities is offered, and particular notice is paid to the campaign of 359, while chapter V looks at the role of Armenia and especially of its southern provinces, the regiones Transtigritanae, in the conflict. The local communities of Mesopotamia are investigated in chapter VI, and in the final chapter I give an impression of the effect which nomadic Saracens had on the imperial frontiers. I conclude that Constantius should be judged as a responsible and careful emperor, who succeeded in preserving the integrity of the eastern frontier in the face of a formidable and determined enemy. In six appendices I present observations on the distribution of auxiliary units in the Mesopotamian provinces, the Romans' retreat from Ctesiphon in 363, the Persians' use of war-elephants and their lack of artillery, the chronology of fourth century Armenia and dromadarii in the Roman army. Five maps, one plan and twelve photographs accompany the text.