In the 6th century, Denmark experienced a severe climatic event that significantly altered the country’s natural environment. A recent research study by the National Museum of Denmark has revealed that an unusual weather shift between 539 and 541 may have inspired the myth of Fimbulvinter in Norse mythology. Fimbulvinter describes a three-year-long winter devoid of summers, foretold in connection with Ragnarok, the series of events that lead to the end of the world.

Researchers analyzed growth rings from 104 pieces of oak wood dating back to this period and found evidence that growing conditions drastically deteriorated in 539. Senior researcher Morten Fischer Mortensen explained that this period of extreme cold was likely caused by a series of significant volcanic eruptions in both Central America and Iceland. These eruptions enveloped the globe in ash and sulfur gases, causing a dimming of sunlight and preventing crops from maturing.

Written sources from the Mediterranean region and China also report similar phenomena, but this is the first time Danish researchers have documented that Denmark was similarly affected. This severe event likely had catastrophic consequences for self-sufficient Danish farmers. With crops failing to mature, many large settlements were abandoned, and forests began to reclaim agricultural land. Mortensen suggested that many people must have struggled to survive during these years, leading to the practice of offering their most valuable possessions—such as large gold artifacts like the Gold Horns and the Vindelev Treasure—to appease the gods.

Mortensen posits that the myth of Fimbulvinter, with its depiction of a three-year-long winter without summers, may represent a cultural retelling of this actual climatic disaster. Its profound impact on the population of that time may have been significant enough for it to be passed down through generations as a part of Norse mythology.

The study has been published in the journal “Journal of Archaeological Science Reports,” adding a new dimension to our understanding of how historical climatic events have shaped both nature and mythology.