Re: Sea Peoples
There are significant destruction levels of ALL the Mycenaean palaces that date around 1200BC, ending what we call the Bronze Age.
Palaces at Mycenae, Pylos, Argos, and several other major sites in Southern Greece all have these destruction levels (the final destruction level of the Mycenaean period) marking an end of the Mycenaean period, and these destruction levels carry on over a span of 100 years through Asia Minor and down the Levant into Egypt - marking what looks like a 10 year path of destruction from the north of Greece. It is clear that there was a threat, several Linear B tablets have been found throughout the Peloponnese, especially Mycenaea and Pylos, many of which that date to around 1200 indicate increased garrisons and the construction of new fortifications on the coastline.
At this time we also see the introduction of the new dialect of Dorian that isn't remotely similar to that of the Mycenaeans.
There are several theories, of course one is that there was an invasion from the north that swept through Greece, into Asia Minor, down the Levant and into Egypt. A second is that it was more of a mass migration rather than a coincided invasion.
A third theory that recently has gained much momentum is that it wasn't in fact an ivasion, but rather an uprising. Many historians are beginning to argue that the 'Dorians' were the lower class, the peasant class if you will, much like the helots of Sparta, that lived in southern Greece during the Mycenaean period. According to this theory, the Mycenaeans were the upper class and that is why their dialect prevailed furing the period, and they were the ones that lived in the great palaces. The theory suggests a coincided uprising of this lower, peasant class that overthrew the Mycenean upper class resulting in the destruction of the palaces and the establishment of the Doric cluture. This theory does however have issues with connecting it with the destruction levels in the East, although it could very well be seperate issues, or the Myceneans were pushed into Asia Minor. This theory is under intensive research at the moment. The linear B tablets do back up this theory, as the Myceneans may have suspected the uprising and began to increase garrisons and fortifications.
A fourth theory that used to be popular but is losing steam is that it was actually a massive war between the Mycenean cities that destroyed the palaces and the the entire culture, and the Dorians swept in from the north and claimed the land.
One last side note is that the most prominent destruction level at the site of Troy occured at the same period as the Mycenaean destruction levels... sparking much debate around the idea of the Trojan Wars. And of course this is the same time of the Hittite collapse as well.