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Millennia of human history have seen many years of scarcity, famine, plague, and war. A new wave of research by historians and scientists singles out one year, however, that was uniquely catastrophic, not just in a local but in a global sense: the year 536 and the ensuing dark age of the 540s. They were ushered in by a mystery volcanic eruption and subsequent events.

No Sun, No Shine

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The beginning of 536 was marked by strange occurrences all over the Northern Hemisphere. The sun turned an eerie blue as it struggled to shine through the darkened skies. Days were turned into nights, and even at midday, there were no shadows. Suffering an affliction normally reserved for lunar or solar eclipses, the inhabitants of the Eastern Roman Empire, from Constantinople to Italy, reported seeing the sun half-covered, like it was an ordinary, permanent eclipse. The summer of 536 was not much different. The sun, too weak to fight its way through the choking blanket of volcanic aerosols, still shone very dimly.

Confirming the historical records, climate reconstructions for the 6th century have revealed that this event was indeed remarkable. Summer temperatures fell by up to 2.5°C in Europe, and the cooling lasted for more than one year. Follow-up eruptions in 539 and 540 took the temperature even further downwards, and a subsequent event around 547 extended the cooling even longer. These eruptions are now identified as the onset of the Late Antique Little Ice Age, a century-long period of climate change that affected the physical and political world of antiquity.

A Total Collapse

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The consequences of this sudden cooling were disastrous. Reduced growing seasons and unexpected frosts ruined harvests throughout Europe, the Middle East, and Asia. Sour grapes, stone-hard apples, and total crop failures became common. Grain became so rare that people were reported by early medieval sources as being unable to buy even the small amounts necessary to stave off starvation, even with the purchasing power of gold.

Mass starvation led to weakened immune systems, which in turn made people vulnerable to disease. In 541, an outbreak known as the Plague of Justinian began. The epidemic would eventually cause the loss of tens of millions and seriously weaken the Byzantine Empire. In Europe and Asia, entire societies struggled against the ravages of hunger, cold, and fear. There are surviving letters from administrators of the period detailing famine relief, food shortages, and “a total disorder in the course of the seasons”.

In addition to the hardships it caused, this cold snap also brought about the collapse of entire civilizations. In search of food, populations shifted. Kingdoms fell. Long-standing political entities experienced turmoil that they never fully recovered from.

The year 536 AD was a dramatic demonstration of the vulnerability of human societies to global environmental change. The eruption of a single volcano caused a darkening of the skies, disruption of the climate, collapse of economies, and redirection of the course of world history. The ancient world was powerless to know, let alone prevent, what was going on; science has now provided a window on how remarkable a time it really was.