Mount Tambora

On April 5, 1815, Mount Tambora exploded. The massive volcanic eruption lasted ten days and completely ravaged the Indonesian island of Sumbawa. 

On April 10, Tambora  put 11 cubic miles(!) of rock, ash and dust in the air (versus Krakatoa's 6 cubic miles) killed 50,000 people, extinguished the language of Tambra, lowered the world temperature by one degree centigrade, caused crop failures all over the world and created the year known as "the year without a summer."

The eruption  was one of the most powerful in recorded history  It created a layer of ash in the atmosphere that blocked the sun, caused crop failure throughout the world with death of livestock. It snowed in New England in July. And starvation: 200,000 Europeans starved.
A Vermont woman named Eileen Marguet wrote of that dark summer in this poem:

It didn’t matter whether your farm was large or small.
It didn’t matter if you had a farm at all.
’Cause everyone was affected when water didn’t run.
The snow and frost continued without the warming sun.
One day in June it got real hot and leaves began to show.
But after that it snowed again and wind and cold did blow.
The cows and horses had no grass; no grain to feed the chicks.
No hay to put aside that time, just dry and shriveled sticks.
The sheep were cold and hungry and many starved to death,
Still waiting for the warming sun to save their labored breath.
The kids were disappointed, no swimming, such a shame.
It was in 1816 that summer never came.