Philistia (Hebrew: פלשת, Pleshet) was a Pentapolis in south-western Levant, comprising Ashkelon, Ashdod, Ekron, Gath, and Gaza, established by migrant tribes (possibly the Sea Peoples), called the Philistines c.1175 BC. The establishment is attributed to the defeat of Sea Peoples by Egyptian ruler Ramses III and their settlement in south-western Canaan. The Pentapolis was in constant struggle and interaction with the neighbouring Egyptians, Israelites and Canaanites, gradually absorbing the Canaanite culture. Philistia is described to have ruled major parts of southern Canaan at the peak of its expansion, but was eventually conquered and subdued by neighbouring Israelites. The Pentapolis ceased to exist following the Assyrian conquest of the Levant in 722 BC. Philistia is thought to be the precursor to the Hellenic and Roman term Palaestina (Palestine).
Biblical scholars often trace the word to the Semitic (probably also Afro-Asiatic language family) root p-l-š (Hebrew: פלש) which means "to divide", "go through", "to roll in", "cover", or "invade". In Biblical Hebrew, the relation to Philistia or Pleshet is as an "invaded land". The name is thought to be transliterated into classical Greek language as Palaestina, first mentioned in the writings of Herodotus.