There is a papyrus suggesting Ramses III was murdered, and now an examination of his mummy suggests someone slit his throat....
this is not Ramses the Great who is supposed to be the one who had problems with Moses and the local union of Hebrew Construction workers (who went on strike and skadaddled into the nearby desert). (other folks say Moses argued with the son of Ramses the great, since the bible only states they worked on a city named after Ramses, not for Ramses himself. Lots of other conjectures about when it occurred, if it happened at all, but that's another story)
This is a later one, who fought the sea peoples and the Libyans, eventually resettling some of the sea peoples in Canaan, who became known as the Philistines and the bad guys of the bible.
These times are called the "Bronze age collapse" and lots of theories about it.
Wikidpedia article on Ramses III here.
The sea peoples might be related not to the volcano of Thera, which decimated the Minoan civilization, but perhaps a cooling spell related to Hekla 3, an Icelandic volcano.
Or maybe the Greeks had it right when they blamed the sons of Hercules who came back and took Greece over after the armies and power of the Mycenean states were weakened by a war trying to get back Helen (and control the trade routes to the Black sea).
But anyway, the country went broke with all the wars, there was a famine, and then the coup.
The PhysOrg article also mentions another young man's mummy that is though to be the executed prince behind the plot.