Researchers recently identified the lowest point in time for humans, A.D. 536. As Harvard historian Michael McCormick told Science Magazine, “It was the beginning of one of the worst periods to be alive—if not, the worst year.”
CNN notes during this time, a year-and-a-half-long fog settled over much of the Northern Hemisphere resulting in failed harvests and wide-spread famine.
Researchers are believed to have determined the cause of the deadly fog: a volcano that erupted in Iceland. According to Live Science, their study published in November analyzed the contents of a 2,000 plus-year-old ice core sample from the Swiss Alps, which they found contained remnants of volcanic glass traced back to Iceland.