In Norse mythology Fimbulwinter is the great winter immediately preceding Ragnarök. It may have been inspired by the horrifying real-life events of 536 CE.
In the Poetic Edda, Fimbulwinter is the time when almost all the humans die. It’s not a huge battle or a blazing inferno: it’s a winter. A long winter, three years of snow, which buries the world and leads into Ragnarök, the twilight of the gods and the end of time.
Now, this is mythology… mythology about the future, no less. And it’s folly to completely attribute mythology solely to archaeological or historical events; the web of creation, recreation, and continuation of mythology is complex and vast. But we have good reason to believe that the Fimbulwinter may have been inspired, in part, by an exceptionally long winter in 536 CE.
You may have heard of 1816, the Year Without a Summer. A volcano in Indonesia erupted, and triggered a global cooling period that led to many strange changes in our world. (I may write about that another time.) Well, the Year Without a Summer saw a drop in the average global temperature of about 0.7°C. It was a large drop, but it was nothing compared to the events of 1200 years before then.
We’re not entirely sure what caused the massive temperature drop in 536, but it was probably a volcanic winter. It may have been several volcanic winters, together dropping global temperatures by as much as 2°C and lasting from 536 until 660 CE. It’s also known as the Late Antique Little Ice Age, and like the Year Without a Summer it’s thought to have triggered a whole host of migrations and demographic changes.
Crop failures and resulting famine spread throughout Europe, and would have been particularly harsh in Scandinavia. Rich Norse nobles buried a whole bunch of gold around then, and it’s thought they did so as a sacrifice to allay the wrath of the long winter. And their experience of that winter of 536 may just have been remembered, absorbed, and eventually churned out as one of the inspirations for the Fimbulwinter.