An Emperor at War

Marcus Aurelius came to the throne in AD 161 already prepared for it by nearly a quarter century of grooming under Antoninus Pius, who had adopted him at Hadrian's direction, but the reign he actually received bore little resemblance to the stable succession that preparation implied. Parthian forces invaded the eastern provinces almost immediately, and the campaign Marcus's co-emperor Lucius Verus led to repel them succeeded militarily but brought home a plague, likely smallpox, that spread through the Roman world and weakened the armies for years afterward. Germanic peoples along the Danube frontier pressed into Roman territory not long after, drawing Marcus personally into years of campaigning far from Rome, the setting in which most of the Meditations was apparently written. His reign also enforced existing Roman law against Christians who refused to perform state religious observance, a policy that produced martyrdoms during his rule and that modern readers have found in tension with his private writing on justice and forbearance, though Marcus left no personal commentary explaining the apparent gap between the two. He died in AD 180, probably of plague or a related illness, while still on campaign, and his son Commodus's disastrous succession was later read by Roman historians as the end of the empire's most stable stretch of leadership.