Ionia (/aɪˈoʊniə/ eye-OH-nee-ə) was an ancient region encompassing the central part of the western coast of Anatolia. It consisted of the northernmost territories of the Ionian League of Greek settlements. Never a unified state, it was named after the Ionians who had settled in the region before the archaic period.
Ionia proper comprised a narrow coastal strip from Phocaea in the north near the mouth of the river Hermus (now the Gediz), to Miletus in the south near the mouth of the river Maeander, and included the islands of Chios and Samos. It was bounded by Aeolia to the north, Lydia to the east and Caria to the south. The cities within the region figured significantly in the strife between the Persian Empire and the Greeks.