How Plagues Shaped the World
Paths have helped topple empires and wipe out civilizations. Traces of DNA in human remains reveal how the microbes managed to wield such power.
In the year 541 AD. Emperor Justinian I looked back on an impressive balance sheet. He had fought successfully against the Goths and Vandals and expanded the Eastern Roman Empire into a vast empire that stretched around the Mediterranean Sea. But he was not allowed to enjoy his victories. Because his dominions were attacked again - this time by an enemy who could neither be found nor seen.
A mysterious plague was rampant in the country and in the capital Constantinople. People developed high fevers, their armpits and groins became painfully swollen, and many became delirious. Even the Emperor fell ill; Rumors of his alleged death stoked panic among the people. The contemporary chronicler Prokopius, who lived in Constantinople, reported that up to 10,000 people died on some days. Justinian survived the epidemic, but his empire remained ravaged by the plague. The Empire lost control of numerous territories and struggled to maintain control of reclaimed Rome.
Scientists to this day debate what caused the plague of 541. Some point to a deadly strain of the plague bacterium Yersinia pestis because the symptoms resembled those of the infamous Black Death of the Middle Ages, which was caused by the same pathogen. Others argue that the Eastern Roman Empire was struck by an influenza virus similar to that which caused the 1918 Spanish flu, which killed 50 to 100 million people. Scientists are also wondering where the epidemic began. Many suspect that it came from Egypt because, according to historical accounts, a similar plague had raged there shortly before…