17. Contributing to the Crisis of the Third Century, the Roman Empire was almost felled by the Plague of Cyprian during the 3rd century
The Plague of Cyprian, named for the Bishop of Carthage who witnessed and described the effects of the outbreak, was a pandemic afflicting the Roman Empire between 249 and 262 CE. Contributing to the Crisis of the Third Century, the widespread outbreak resulted in severe shortages of food production and the capacity of the empire to project its military might. At the height of the plague, according to contemporary sources the outbreak was responsible for as many as five thousand deaths per day in Rome. Concurrently, the persecution of Christians in the Roman Empire spiked, with acolytes of the fledgling religion scapegoated for the tragedy.
Nearly bringing about the end of the Roman Empire, with a rapid succession of usurping emperors and unrepentant in-fighting, the frontier, insufficiently manned and weakened, collapsed. Only the efforts of subsequent emperors, including notably Diocletian and Constantine, saved the state from implosion and total erasure. Given the nature and spread of the pandemic, it is generally believed that the inhabitants of Rome enjoyed no immunity to the condition and thus had not been exposed previously. As a result, the most prominently subscribed to suggestions include influenza, Ebola, and measles.