History of Wars Summary 17 - Justinian's Expansionist Wars 8 Expanded Territories and Continuous Warfare

While expanding territories in the West, the Eastern Roman Empire continuously faced threats from the East and North. In 540 AD, Khosrow I of the Sasanian dynasty invaded Eastern Roman territory, reigniting the war with Persia. Justinian had to dispatch troops to both the West and the East simultaneously, and the war repeatedly saw truces and restarts. The troops and expenses required for the Eastern front became a significant burden for maintaining the Western conquests. In the Balkans, Slavic groups and various nomadic forces also crossed the borders, forcing the emperor to repair fortifications and deploy troops along the Danube. Thus, although the empire's territory greatly expanded, its military was inevitably spread across multiple fronts. In Italy, in particular, resistance and chaos continued even after the conquest, and garrisons were needed in North Africa and Iberia. Justinian's territorial expansion was not merely about acquiring conquered lands but became a challenge of simultaneously defending and governing vast regions. This burden became increasingly apparent as the emperor's reign progressed into its later years.