From Mental Floss (hat tip: Tom MacMaster):
A Massive Volcanic Eruption in Alaska May Have Doomed the Roman Republic
The fall of the Roman Republic gave rise to the Roman Empire, making it one of the most significant events in Western history. According to a new study published in Proceedings of the National Academy of Sciences, it may have been hastened by a volcanic eruption on the other side of the world.
The year 43 BCE was a time of social unrest in ancient Rome. Julius Caesar had been assassinated a year earlier, sparking fights for political control that led to the fall of the Roman Republic and the Ptolemaic Kingdom. This was also a period of devastating climate change. Accounts from the era describe crop failure, famine, and disease plaguing the Mediterranean region as temperatures dropped. The new study from an international team of scientists connects these disasters to the massive eruption of an Alaskan volcano around the same time.
Researchers looked at Arctic ice cores containing millennia of geological data and found that a volcanic eruption—one of the largest of the past 2500 years—occurred in 43 BCE. Further analysis of the volcanic material inside the cores linked the event to the Okmok volcano in Alaska. Using Earth system modeling software, researchers digitally recreated the impact of the volcanic activity on a global scale. The model showed colder, rainier weather patterns in the Mediterranean for two years following the eruption, with seasonal temperatures dropping more than 10°F below normal in some places.
Read the whole thing, including speculation that the eruption of the Icelandic volcano Hekla triggered the Bronze Age Collapse. Of course, it’s difficult to establish conclusive proof for either of these, but both are quite plausible. (Query: did an eruption event cause the Great Famine of the fourteenth century, and if so, have any candidates been proposed?)