King of Tambora
Short version: probably largest volcanic eruption in historical times, ~ 100 km3 of lava and ash. Pyroclastic eruption, magma chamber collapse leaving a km deep, 8 km wide caldera, top 1.5 km of mountain collapsed in.
Over 100,000 people died.
Sulphate aerosol emission lead to "year without summer" in 1816 and widespread crop failure.
Presented interesting new fieldwork, including the discovery of archaeological remains that may be part of the legendary capital of the kingdom of Tambora (which was totally destroyed, leaving only 4 survivors [they were on a tall rocky hill], apparently viet-khmer descended coastal traders, 48 words of their language survived on record).
Anyway, he told us a story, aprocyphal, but interesting, and I could find no record of it on the web (well, with a 30 sec google using no more than 4 keywords, that's barely trying).
So, from memory, paraphrasing, here goes:
Once upon a time, a visitor from another island came to the kingdom of Tambora.
He went to the local mosque, in the capital town of Tambora, for prayers. As it happened, the king and his retinue were there also at prayer, but the king had brought a favourite dog with him into the mosque.
The visitor was upset by this, and spoke loudly and widely against it in the town that day. Word got back to the king, and he bade the visitor to come dine with him. During the meal, unknown to the visitor, the king had the man served pieces of the dog cooked to seem like one of the courses the others were eating.
The next day, the visitor heard in town the evil the king had done, and he became very angry and denounced the king.
The king heard of this, and ordered his guards to seize the visitor, take him up the mountain, and kill him on the spot. Which they did.
As they walked down, they noticed smoke started rising from the place where they committed the murder.
After two years of small low level eruptions, the mountain exploded killing everyone.
There is a lesson or two here.
One is that you should not violate the rules of hospitality and abuse visitors.
The other is that, even if you are the King of Tambora himself, you should heed criticism, even (or especially) from outsiders. They might be right.