The "Sea Peoples" were dispossessed victims of the disturbances at the end of the Late Bronze Age – including but not limited to a devastating pandemic and prolonged drought – and there is a growing consensus that the migrations were more of a refugee crisis than an invasion. Many of these refugees originated in the eastern Mediterranean, particularly Greece, the Aegean islands, and western Anatolia, while others seem to have originated in south-central Europe. Unfortunately, most of our information about them comes from Egyptian historical inscriptions, which are often highly unreliable. I wrote more about the unreliability of Egyptian historical inscriptions in this post.

In any case, several of the groups are attested more than 200 years before the end of the Bronze Age, often allied with the major powers like the Egyptians and Hittites. In the Battle of Kadesh (ca. 1280 BCE), for instance, the Sherden fought on behalf of the Egyptians, and the Lukka fought on behalf of the Hittites. They were also often hired as mercenaries by the smaller city-states in the Levant. For example, in two letters to the king of Egypt (EA 122 and 123) dating to around 1340 BCE, the vassal king of Byblos complained that the Egyptian governor of nearby Kumidi killed a Sherden within his town (presumably a mercenary hired by Byblos), and the outraged people of Byblos demanded justice.

Paḫuru perpetrated a great misdeed against me. He sent Sutean men, and they killed a Sherden and took three men (as captives) into the land of Egypt. And for how many days has the city been enraged at me! And behold, the city is saying, “A deed that has never been done since time immemorial has been done to us!” So send the men (back to Byblos) lest the city commit rebellion.

I've written more about the Sea Peoples in these posts:

• What do we know about the so-called Sea People's origins?

• Tell me about the Philistines vs others in the Levant 1200 to 800 BCE

• Karatepe and Çineköy inscriptions: Luwian and Phoenician and Sea Peoples