We have a fair knowledge of Holocene volcanic activity, but further back is quite murky, with the exception of some very large eruptions like Mt Toba circa 74,000 BC (which nearly wiped out all of the existing homo sapiens population... estimates range from a few hundred to a few thousand survivors)
Most of the Neanderthals were gone by that time, but I think there have been a find or two in the time frame I mentioned.