We have discussed the plagues that disrupted the Roman and Byzantine Empires before. (See threads below,) This video is a nice review of the three of the most devastating plagues: The Antonine Plague also known as the Plague of Galen (165-180 AD): Antonine Plague - Wikipedia The Plague of Cyprian (249-262 AD): Plague of Cyprian - Wikipedia The Plague of Justinian (541-549 AD): Plague of Justinian - Wikipedia