The emperor Theodosius I (AD 379–395) was one of the most remarkable figures of the late antique period. In the face of religious schism, political turmoil, and barbarian threats he managed to maintain imperial power and forge a political dynasty that would dominate both east and west for over half a century. This study, the first English language biography in over twenty years, traces his rise to power and tumultuous reign, and examines his indelible impact on a rapidly changing empire.

Mark Hebblewhite completed his PhD at Macquarie University, Australia in 2012 and has taught widely in the field of Ancient History. His research interests centre on the ideology and politics of the later Roman Empire, with particular reference to the role of the army. He currently works at the Australian Catholic University.