A colony of Megarians establishes Heraclea Pontica…
561 BCE to 550 BCE
A colony of Megarians establishes Heraclea Pontica (present-day Eregli on the Black Sea coast in about 560-558 BCE; they name it after Heracles, who the Greeks believed entered the underworld at a cave on the adjoining Archerusian promontory (Cape Baba).
The colonists soon subjugate the native Mariandynians but agree to terms that none of the latter, now helot-like serfs, be sold into slavery outside their homeland.
Prospering from the rich, fertile adjacent lands and the sea-fisheries of its natural harbor, the colony extends its control along the coast as far east as Cytorus (Gideros, near Cide).