A team of researchers led by Harvard archaeologist and historian Michael McCormick has identified 536 AD as the worst year in human history, according to a study published in the journal Antiquity and reported by Futura.
McCormick said the year marked the start of one of the worst periods to be alive, if not the worst year itself. At the time, the world was in the tenth year of the reign of Justinian the Great, emperor of the Byzantine Empire.
Volcanic eruptions and years of darkness
The researchers point to volcanic eruptions as the likely cause. Eruptions can trigger what scientists call volcanic winters, when airborne particles block sunlight and cool the planet. Similar events have shaped human history before, including population declines 74,000 years ago and mass migrations across 19th century Europe.
Recent analysis found traces of volcanic ash in ice cores from the Colle Gnifetti glacier, on the border between Switzerland and Italy, pointing to an eruption in 536 that scattered ash mixed with ice.
An eyewitness account from the sixth century
Byzantine historian Procopius of Caesarea described the most terrifying sign of that year: the sun gave off light without brightness, like the moon, for the whole year, resembling an eclipse because its rays were not clear as usual.
The cooling and prolonged winters caused widespread famine. Tree rings in Greenland and ice cores from Antarctica show two more major eruptions in 540 and 547 deepened the crisis, producing the coldest years in the previous 2,300 years.
Plague strikes the Mediterranean
In 541, the Plague of Justinian struck the entire Mediterranean basin. Outbreaks sometimes killed tens of thousands of people a week, hastening the collapse of the Eastern Roman Empire. Historians say the pandemic lasted until 767.
A sign of recovery eventually emerged. Lead found in ice cores from 640 shows people had resumed mining and smelting silver, a small light at the end of a centuries-long darkness.
