In around 535 AD the volcano at Krakatoa exploded with a
force equivalent to two billion Hiroshima sized
A-bombs, throwing a vast amount of rock and volcanic
debris into the atmosphere and precipitating a
Naturally some people say that this is a load of
old nonsense and that it was in fact a comet that
struck the earth with a force equivalent to etc
Whatever theory is correct, (and personally I favour Krakatoa) something dramatic and
calamitous clearly happened as,
- we have the scientific evidence from tree ring
data that shows post 535 AD a sudden decline in the
rate of tree growth which lasted for 15 years
- we have the historical evidence such as that of
Procopius, writing of 536 AD that,
The Sun gave forth its light without brightness, like the Moon, during this whole year, and it seemed very much like the Sun in eclipse, for the beams it shed were not clear.
- or of Cassiodorus, writing of the same period,
We have had a winter without storms, a spring without mildness, a summer without heat. When can we hope for mild weather, now that the months that once ripened the crops have become deadly sick under the northern blasts? ... Out of all the elements, we find these two against to us: perpetual frost and unnatural drought.
Hence there was a shift in the global climate, harvests failed, there were severe droughts,
everything got colder, and the bubonic plague made its first appearance in Constantinople in 542 AD, sweeping fairly rapidly across Europe and hitting Britain in 547 AD. The plague returned at regular intervals afterwards and according to Edward Gibbon lasted for 52 years. The end result being a significant depopulation particularly of what had been the more economically developed parts of the world, such as the Roman Empire and its former territories.
These events are believed by many to have been a significant factor in such historical events such as the fall of the Gupta empire in India, the Islamic conquests in the Eastern Mediterranean as well as the conquest of Britain by the Anglo-Saxons.