Robert Drews wrote The End of the Bronze Age, and he presents a number of theories about what ended the Bronze Age. The most likely result was the destruction of every known city (except for Memphis and Thebes) by military conquest by the Sea Peoples. Several of the cities were destroyed repeatedly, so it appears that the city burners would return to ensure the destruction of the cities.
The name Sea Peoples comes from a French translation of some Egyptian hieroglyphics. The tribes mentioned as being part of the Sea Peoples include names from what is now called the Baltic Sea and Afghanistan. One of the swords that became popular at this time - the Naue Type 2 - was developed in the Baltic area. Military tactics during the Bronze Age centered around chariots and large levies of infantry. The chariots were a sign of wealth. In 2 Chronicles, Solomon had 1400 chariots. After the end of the Bronze Age, javelins, greaves and iron blades became common while chariots mostly vanished from the battlefield. It is likely that a military force with new tactics that the existing powers were incapable of countering was able to destroy all existing armies (Genghis Khan basically did this also). Some written tablets in Ugarit were found in the 19th Century in the type of oven used for baking tablets before being sent off. It mentioned the Sea Peoples arriving in port with 30-40 ships. The city was destroyed before the tablets were dried and able to be sent off requesting military assistance. Other tablets in the oven were mentioning prices for things that were not consistent with drought or famine (for example, a tunic cost 3 ewes).
The Sea Peoples had destroyed every city (going clockwise) from what is now Greece, through Turkey, through the Levant and Mesopotamia all the way to Gaza. The Egyptians waged several battles with them in 1208 BC and 1176 BC. The last known battle with the Sea Peoples was that one in 1176 BC. By then, they had engaged in at least 30 years of continuous warfare during an era when the life expectancy of a person was less than that. As far as we know, there weren't any Bronze Age cities north or west of Greece. The Sea Peoples killed everyone who could read or write, and in several cases, returned to re-destroy cities that were being rebuilt. As a result, there was no one left to record what their names were, so instead, we named the entire Bronze Age "pre-mycenean" based on Mycenea - the city that was built near the old ruins. That the Sea Peoples never settled near any cities they destroyed indicates that they were a raiding force and not a migratory one.
From the stelae that the Egyptians built to commemorate their pyrrhic victory over the Sea Peoples, they showed stacks of arms and penises. The Egyptians had a habit of cutting off penises of uncircumcised defeated warriors and cutting off the hands of the circumcised (or maybe I have that backwards). The records of what they accumulated at the 2 recorded battles showed a mix of hands and sex organs. Which is far more consistant with a collection of disparate tribes than of a single invading force. Tribes in those days tended to be cut or not as a whole. Not something one could mix and match (see story of Dinah in Genesis 34). If you watch Heritage: Civilization And the Jews (it is in the first episode), you'll see the stela that mentioned Israel being destroyed about 1200 BC.
Archeological excavations show that the destruction was consistent with a sudden attack and inconsistent with natural disasters (earthquake, fires, drought and so on) because of how folks tended to hide valuables inside walls. If the destruction was long-term, such as drought, folks would uncover and remove their valuables. If the destruction was sudden like an earthquake, there would be attempts to excavate the valuables. If the destruction was sudden military conquest, the valuables would remain inside walls for centuries.