When I was a child, I asked my mother whether it was possible for the sun to stop shining. She said no—it would be the end of the world. It turns out she was half right. In the year 536 AD, across much of the known world, the sun did stop shining—or at least, it dimmed to a sullen, bluish glow. The sky filled with haze. The crops failed. The wine soured. People starved. And though it wasn’t quite the end of the world, it was one of the worst years to be alive in recorded history.

That’s not me exaggerating. That’s the emerging consensus of climate historians, scientists, and even economists who now study what they call “environmental shocks.” And strangely enough, we know more about the events of 536 than we did even ten years ago—because of ice cores, tree rings, and renewed attention to ancient sources.

If I hadn’t kept science on at A-Level, I might not have stumbled across any of this. And I might not have appreciated the irony: that all the environmental hysteria in today’s school textbooks—most of it designed to justify government theft and corporate land-grabs—has inadvertently done some good. It’s forced historians and scientists to work together again. It’s reopened questions about the past that the liberal arts forgot to ask. And it’s allowed us to begin rewriting history in a way that gives proper weight to non-human forces like weather, disease, and volcanic dust.

This essay, like my previous one on the climate impact of the Antonine and Cyprian plagues, is inspired by Dr Gabb’s lecture on “Nature and Empire.” It focuses on 536 AD—the year that history went dark.

1. The Historical Testimony: Darkness Described

Cassiodorus, a Roman administrator writing in 536, offered the most striking Western description of the sky that year. In his letter (Variae 12.25), he wrote:

The sun…seemed to have lost its usual light and appeared bluish in colour; the moon, too, though full, was empty of splendour.

He added that the sun’s dimness and the dry north wind meant fruits did not ripen and the wine tasted of sour grapes.

Procopius, the great Byzantine historian, wrote of the same strange phenomenon in his Wars of Justinian:

During this year, a most dread portent took place. For the sun gave forth its light without brightness…and it seemed exceedingly like the sun in eclipse, for the beams it shed were not clear. (Wars, 4.14.5)

John Lydus, writing in Constantinople, called it a “moist fog over land and sea” (De Ostentis, 6.6), though he also said it came with dry winds and no rain. Michael the Syrian, relying on earlier Syriac sources, described “a thick mist over the earth that obscured the sun like a sackcloth.”

The Liber Pontificalis claims that the famine caused by the 536 event drove mothers in Liguria to cannibalism:

In those days…mothers ate their children (Liber Pontificalis, Vita Vigilii, 60).

In Syria and Mesopotamia, John of Ephesus wrote that:

There was a sign from the sun, the like of which had never been seen or reported before… The sun became dark and its darkness lasted for eighteen months.

These records do not all agree on the details, but they’re unanimous on the basics: the sun dimmed, the temperature dropped, and life got worse.

2. The Science: What Happened to the Sky?

The cause remains contested. Richard Stothers and Michael Rampino’s 1983 study in the Journal of Geophysical Research proposed a massive volcanic eruption, possibly in the tropics. Sulphate particles injected into the stratosphere would have reflected sunlight for months or years, producing exactly the kind of “dry fog” described by the ancients.

Ice cores from Greenland and Antarctica contain evidence of volcanic activity around 536. But while sulphate spikes are visible, no single eruption site has been definitively identified. Candidates include Iceland, Alaska, Central America, or the tropics—perhaps even multiple eruptions close together. Some researchers now argue for a second massive eruption around 540, compounding the disaster.

Alternative theories include a comet or asteroid impact, but the absence of an impact crater has made this idea less popular. Tree ring evidence—especially from Scandinavian pines—shows severe growth suppression from 536 to 545, supporting the theory of cooling. In the Southern Hemisphere, similar growth dips occur a few years later, perhaps reflecting the spread of atmospheric dust.

In short, something blocked the sun. Most likely, it was volcanic. But we still don’t know where or exactly when. And the effects were not uniform—while some places froze, others merely dimmed.

3. The Fallout: Famine, Recession, and Plague

Climate events never occur in isolation. The year 536 was followed—less than a decade later—by the Justinianic Plague, which may have killed a third of the Mediterranean population. Whether the plague and the haze are causally linked is unclear, but the coincidence is alarming.

What we can say is that the dimming of the sun led to crop failure. The poor harvests meant food shortages. Grain prices surged. Cassiodorus noted soaring costs and had to order emergency grain distributions in Venetia and Liguria. But it wasn’t just about food. In Egypt, rent contracts from the Fayyum show wide fluctuations in land value and taxation, suggesting an unstable economy. In Petra, tax receipts show arrears both before and after 536—but there’s a notable dip immediately after.

In Constantinople, the government responded by altering the coinage. The copper follis was re-weighted in 538, perhaps in an attempt to stabilise the economy. No law mentions the haze, but a few years later, Justinian began to associate plague with divine wrath. In 568, homosexuality was blamed for God’s punishment.

Archaeological records suggest ongoing construction of churches and public buildings even during this period. But in rural areas, signs of abandonment increase. Trade declined. Hoards of buried coins increase—a classic sign of social insecurity.

4. Beyond the Mediterranean: A Global Event?

The Chinese Book of Liang notes that in 536, the star Canopus was invisible—an observation interpreted as evidence of atmospheric opacity. But Chinese sources don’t mention a darkened sun or famine.

In Ireland, the Annals of Ulster and Annals of Inisfallen record “a failure of bread” in 536 and 539. In Mesoamerica, signs of drought appear in the Lake Cuitzeo sediments. The 536–545 cooling may have triggered or accelerated the collapse of Teotihuacan. Tree-ring evidence from Siberia, Chile, and New Zealand shows suppressed growth.

That said, not all regions suffered equally. Egypt seems to have coped relatively well. Syria was hit harder. And the Eastern Roman Empire, while shaken, survived.

5. Interpreting the Event: Was 536 a Turning Point?

Some scholars, like Kyle Harper, argue that the event of 536 and the plague that followed began the long decline of the ancient world. Others are more sceptical. Arjava (2005) insists that the event had limited impact in the eastern Mediterranean. Buildings still went up. Law codes continued. Life carried on.

My view—probably close to Harper’s—is that 536 was not the end of Antiquity, but a warning. It showed how fragile the imperial system had become. Ancient civilisation could survive bad emperors and civil war, but not everything. When the sun disappeared, the system strained—and ten years later, when plague hit, it cracked.

In a world without industrial farming, refrigeration, or global trade, the margin for error was slim. In 536, the margin vanished.

6. What This Means for Today

I don’t believe in climate doomsday cults. But I do believe that natural forces—dust, wind, water, sun—can unmake what humans spend centuries building. The lesson of 536 is not that we should pay higher taxes to save the planet. It’s that the planet doesn’t care about our plans.

And when the skies change, so must we.

Bibliography

• Agapius of Membij. Universal History. Trans. A. Vasiliev. Patrologia Orientalis 5 (1910): 557–692.
• Arjava, Antti. “The Mystery Cloud of 536 CE in the Mediterranean Sources.” Dumbarton Oaks Papers 59 (2005): 73–94.
• Barnish, S.J.B., trans. Cassiodorus: Variae. Liverpool: Liverpool University Press, 1992.
• Charles, R.H., trans. The Chronicle of John, Bishop of Nikiu. London: Williams & Norgate, 1916.
• Davis, Raymond, trans. The Book of Pontiffs (Liber Pontificalis). Liverpool: Liverpool University Press, 1989.
• Dewing, H.B., trans. Procopius: History of the Wars. Cambridge, MA: Harvard University Press, 1914–1928.
• Garnsey, Peter. Famine and Food Supply in the Graeco-Roman World: Responses to Risk and Crisis. Cambridge: Cambridge University Press, 1988.
• Harper, Kyle. The Fate of Rome: Climate, Disease, and the End of an Empire. Princeton University Press, 2017.
• Honore, T. Tribonian. London: Duckworth, 1978.
• Lamb, H.H. Climate, History and the Modern World. 2nd ed. London: Routledge, 1995.
• Rowlandson, J. “Agricultural Tenancy and Village Society in Roman Egypt.” In Agriculture in Egypt from Pharaonic to Modern Times, ed. A.K. Bowman and E. Rogan. Oxford University Press, 1999.
• Stothers, Richard B., and Michael R. Rampino. “Volcanic Eruptions in the Mediterranean Before A.D. 630 from Written and Archaeological Sources.” Journal of Geophysical Research 88, no. B8 (1983): 6357–6371.
• Telis, I., and E. Chrysos. “The Byzantine Sources as Documentary Evidence for the Reconstruction of Historical Climate.” In European Climate: Reconstruction from History and State, Methods, ed. J.B. Frenzl. Stuttgart: Paleoklimaforschung, 1992.