536 AD: The Worst Year in History?

If you thought 1349 (Black Death) or 1918 (Spanish flu) were history’s darkest years, think again. Harvard historian Michael McCormick calls 536 AD the worst year to be alive — and for good reason.

A Year Without Sunlight

In 536, a mysterious fog blanketed much of Europe, the Middle East, and Asia, darkening the skies for over a year. Temperatures plummeted, crops failed, and famine swept continents. China recorded summer snowfall, and Ireland faced food shortages from 536 to 539.

Then Came the Plague

Just a few years later, in 541, the Plague of Justinian devastated the Byzantine Empire, killing millions — up to 50% of some populations — accelerating the empire’s decline.

The Volcanic Clue

What caused this global darkness? Recent ice core studies from Switzerland point to a massive volcanic eruption in Iceland in early 536, followed by others in 540 and 547. These spewed ash and sulfur into the atmosphere, blocking sunlight and cooling the planet — triggering over a century of hardship.

A Recovery Hidden in Ice

By 640 AD, a spike in lead pollution in the ice (linked to silver mining) hinted at Europe’s economic recovery — trade was resuming, and society was stabilizing. But when the Black Death hit in the 1300s, lead vanished again, marking another economic crash.

Why It Matters

This mix of historical records and climate science is revolutionizing how we understand the past. The integration of high-resolution environmental data gives a powerful new lens on how natural disasters reshaped civilization.