
What does an Indonesian volcano have to do with Frankenstein's monster? The answer lies in the year without a summer in 1816.
Mary Shelley and others visited Lord Byron at Villa Diodati, near Switzerland's Lake Geneva in the summer of 1816. While there the company's plans were thwarted by persistently dreary weather and were forced to stay indoors for three days. To pass the time they started reading and telling old ghost stories then, at the suggestion of Lord Byron, started to write their own. It is during this time that Mary Shelley started what would later become "Frankenstein - or The Modern Prometheus".
The most likely cause of the inclement weather that plagued the whole northern hemisphere and kept Lord Byron, Mary Shelley and others indoors in the summer of 1816 was a volcanic eruption a year earlier in Indonesia. The volcano known as Tambora, once over 13,000 feet tall erupted in April of 1815 with a force estimated at 100 times than the eruption of Mount St. Helens in May of 1980. This Tambora eruption, likely the largest in recorded history, ejected between 100-150 cubic kilometers of volcanic ash into the atmosphere. The ash blocked enough sunlight to markedly cool global temperatures and provide the setting for writing Frankenstein.
Frankenstein was not the only literary product of the year without a summer. John Polidori, Lord Byron's physician, wrote "The Vampyre" preceeding of Bram Stoker's "Dracula" by nearly eighty years.