Nope, it wasn't Mt. Vesuvius' monster eruption, which buried Pompeii and other nearby towns in feet of ash.
It was the explosion of Mount Tambora in Indonesia in 1815. The volcano, which is still active, is located on Sumbawa Island and is one of the tallest peaks in the Indonesian archipelago.
Tambora's volcanic activity reached a peak in April 1815, when it erupted with an explosion so loud that it was heard on Sumatra Island, more than 1,200 miles away. The eruption ranked a 7 (or "super-colossal") on the Volcanic Explosivity Index, the second-highest rating in the index.
Only a handful of such explosive eruptions have occurred in recorded history, and Tambora's tempest was believed to be the largest eruption since Lake Taupo in A.D. 181.
The death toll from the eruption was estimated at 71,000 people, and clouds of heavy ash descended on many far-away islands.