Way back in the 500s Krakatao or another one or maybe several in different parts of the world went off in close succession to each other and the Chinese were able to record in the royal annals "A Loud Noise" ~ then they promptly fell into 300 years of Dark Age without civilization or wealth.
I read once, that at any given time there are 40 volcanoes erupting on earth somewhere........
that would also explain Europe’s slipping into the Dark Ages...
The most recent evidence is that the 535[536 eruption was the Ilopango Caldera in El Salvador, not Krakatau.