The Sea Peoples are supposed to be a seafaring confederation that attacked ancient Egypt and other parts of the East Mediterranean. The time was before and during the Bronze Age collapse (1200–900 BC).
During the Bronze age collapse, archeological evidence shows the destructions of many cities on the coastlines of the Levant and the Aegean Sea. That may have been caused by invaders from the sea. The exact origins and cultures of the attackers are unknown and so historians call them the Sea Peoples.
Some sources say that they used iron weapons, which the Bronze Age cultures had not yet seen. The cities that they attacked allows one to infer that they were probably naval-based.