While we may know Vikings as ferocious warriors, those ancient Norsemen were not without fear.
In fact, one of their greatest fears may have been etched in stone. It's a fear that still haunts us today.
According to a new interpretation of the world's most famous Viking runestone, the one thing that may have rattled them was climate change.
The research, conducted by scholars at three Swedish universities, suggests the famed Rök stone was more than just a memorial to a dead son.
"The inscription deals with an anxiety triggered by a son's death and the fear of a new climate crisis similar to the catastrophic one after 536 CE," the authors note in a press release.
What prompted Vikings to chronicle their environmental concerns remains largely a mystery. But, like every good mystery, it's wrapped in another mystery — the 5-ton enigma known as the Rök stone. Researchers have long been trying to unravel the secrets of the stone, a stark memorial erected in Sweden in the 9th century.
Its 700 runes, covering all five sides of the slab, have been largely inscrutable to present-day scholars, although some suggest it recounts exploits on the battlefield.
Instead, it may chronicle a different kind of battle — one waged against nature itself.
Research assistant and archaeologist Hans Hildebrand sits beside the Rök Stone. The rune stone was raised in the 9th century by Varin in memory of his dead son, Vämod. (Photo: Swedish National Heritage Board [No restrictions]/Wikimedia Commons)
Study authors say the biggest clue to deciphering the code is recent archaeological evidence suggesting the people of Scandinavia had endured climate catastrophe 300 years earlier. A series of volcanic eruptions brought starvation, lower-than-normal temperatures and mass extinction.
Indeed, Vikings had a name for that kind of blight: Fimbulwinter.
According to Norse mythology, Fimbulwinter — translated directly as "the great winter" — was a brutal spell that brought desolation to the land for three unrelenting years. It was considered a prelude to Ragnarok, or the end of the world.
Fimbulwinter may not have been a myth.
"Before the Rök runestone was erected, [there were] a number of events occurred which must have seemed extremely ominous," notes study co-author Bo Gräslund of Uppsala University in the release. "A powerful solar storm coloured the sky in dramatic shades of red, crop yields suffered from an extremely cold summer, and later a solar eclipse occurred just after sunrise. Even one of these events would have been enough to raise fears of another Fimbulwinter."
Ultimately, Fimbulwinter represented the ultimate battle for survival.
"The powerful elite of the Viking Age saw themselves as guarantors for good harvests," adds co-author. "They were the leaders of the cult that held together the fragile balance between light and darkness. And finally at Ragnarök, they would fight alongside Odin in the final battle for the light."
With global temperatures ratcheting steadily upward in recent years, maybe it's time we heeded the voices of the present, as well as those of the past.
Lest we face a Ragnarok of our own design.