I can’t come down on one side or other (and frankly wouldn’t bother trying) of whether there is sufficient “historical” evidence in the form of written texts etc. to support the 535AD catastrophe theory. Furthermore, having a background in geology I believe that any geo. worth his salt wouldn’t actually waste their time at this point actually looking for the specific volcano that caused the alleged catastrophe (This part of the doco for me thus seemed a pretty pointless wild goose chase in that even if you find the volcano it doesn’t prove much vis a vis catastrophes).

The way to answer the question about whether the worlds civilisations where placed under extraordinary stress lies in two fairly prosaic avenues of enquiry, both pursued but to an insufficient extent, in the doco.

The first one is collection of further tree ring data from around the world (or maybe just further analysis of existing data) and assessing the growth conditions for 535, 536, 537AD in comparison to the average. If you find markedly and generally adverse growing conditions for trees around the world (or at least in the areas for which the “civilizations under stress” theory is being put forward), it can be assumed that the crops on which these civilizations are dependant would also be, on average, strongly adversely affected. Put simply, by what mechanism would all the oaks and pines be having an exceptionally bad time, but the barley, corn, and wheat thriving?

To link the inferred crop stress fairly conclusively to the effects of an extraordinarily large volcanic eruption is then simply a matter of analysing bog, lacustrine, and other sedimentary deposits for extreme (averaged over all areas of concern) input of volcanic ash, backed up by analysis of glacial and ice sheet core data on atmospheric composition for the period.

If you establish both physical conditions, basically anything that may be written in historical texts is a nice bonus to the theory, especially as far as the “human interest” angle goes, but pretty superfluous to knowing if there really was a catastrophe for civilization in general in 535AD. Firmly establishing both physical conditions (which is simply a matter of putting in sufficient effort) would also establish that there must have been.

Yes it did cause lots of climatic and other problems (including, indirectly, the great sickness that hit Justinian East Roman Empire – and the people who traded with it, such as the Romano British in what is now Western England).

I don’t recall anything about this in Bede.

I am nowhere near a volcanologist, but some googling (the advantages of being an insomniac) pointed me to this list of eruptions in that part of the world. It does list an eruption in 540, but makes no specific claims about it. Elsewhere the Taupo eruption is described as the world’s biggest in recorded history. On the basis of this cursory tour of the web, I am skeptical that the 535 eruption was indeed as big as the book makes out, and even more skeptical that it was the transformational event that gave birth to the modern world.

Historically there was also the explosion of Santorini in 1640BC which almost certainly damaged everyone in the vicinity and may have had a lot to do with the end of the Mycenean civilization.

There are potentially far bigger ones in our future. There are at least two areas in the Western US which could go off in the next few centuries that would make even the aforementioned look like firecrackers. You see, Yellowstone isn’t a volcanic region… it is the volcano. Likewise there is a similar and a bit smaller region (if I remember correctly) in the California Mono Lake region.

When Yellowstone next goes up, we get a large part of the US west under a few hundred feet of (or more) of ash and lava.

It’s happened before, just not in recorded history.

So I’d say the thesis is valid in the sense that big volcanoes could do considerable damage to human civilizations, but the evidence is a bit thin for anything quite large enough to do in the world in 535AD.

I’d also be interested in hearing more, particularly form a Vulcanologist who might know exactly how big the 535AD blow up was… and if it is actually dated any where close to that date.