The pagan historian Zosimus, who lived in the Anastasius period in the fifth and sixth centuries, produced a study in Greek called Historia Nova. The aim of the work is to hand down the decline process of the Western Roman Empire to the next generations. According to Zosimus, the process that started with the transition from the Republican administration to the dictatorship system accelerated with the Christianization and barbarization of Rome. At the introduction of the work, Zosimus said that he had intended to explain all the events that adversely affected the empire but after a brief summary from Augustus' accession alone to Diocletian's tetrarchy, he gave a much more detailed narrative until 410, after which the work ended suddenly in the middle of the sixth book, probably because he died. The most significant feature of the work is that Zosimus attempts to deal with all the subjects that match up with the main theme of Historia Nova. The historian's focus is on the barbaric attacks of the empire, religious attitudes and political stance of the emperors, throne struggles and civil wars. For Zosimus, the new series of events that led the empire to chaos after the third century crisis began with the death of Constantinus. According to Zosimus, theological debates and imperial crisis that occured in the reign of Constantinus II, Constantius II and Constans, Constantinus’ sons whom he raised as Christians, contributed to the weakning of the empire along with the threats at the frontiers. In addition, Constantius II’s struggle against Magnentius, who rebelled by taking advange of the riot, was northworty for Zosimus hence it served his purpose. The Battle of Mursa that took place in 351 is regarded by ancient sources and modern researchers as the bloodiest civil war of the Roman Empire. Historia Nova is the only source we have in terms of the details of the war, and the depictions of events and emperor portraits of Zosimus also make the work indispensable. In this study, the interpretations of Zosimus' War of Mursa will be analyzed by comparing with the ancient sources of the era and the effects of the causes and results of the war on the administrative structure and military order of the Roman Empire will be discussed in the light of modern literature. The main purpose of the study is to examine Zosimus' thoughts on decline and fall within the framework of the Battle of Mursa taking into consideration the religious tendencies of the parties and to question the value of Historia Nova as a historical source.
Zosimus, Historia Nova, Constantius II, Magnentius, Battle of Mursa.