Cardia (in
Greek Kαρδία), anciently the chief town of the
Thracian Chersonese (today
Gallipoli peninsula), was situated at the head of the Gulf of Melas (today the
Gulf of Saros). It was originally a
colony of the
Milesians and
Clazomenians; but subsequently, in the time of
Miltiades (late 6th century BC), the place also received
Athenian colonists, as proved by Miltiades tyranny (515–493 BC). But this didn't make Cardia necessarily always pro-Athenian: when in 357 BC Athens took control of the Chersonese, the latter, under the rule of a
Thracian prince, was the only city to remain neutral; but the decisive year was 352 BC when the city concluded a treaty of amity with king
Philip II of Macedonia. A great crisis exploded when
Diopeithes, an Athenian mercenary captain, had in 343 BC brought Attic settlers to the town; and since Cardia was unwilling to receive them, Philip immediately sent help to the town. The king proposed to settle the dispute between the two cities by arbitration, but Athens refused. The town was destroyed by
Lysimachus about 309 BC, and although it was afterwards rebuilt, it never again rose to any degree of prosperity, as
Lysimachia, which was built in its vicinity and peopled with the inhabitants of Cardia, became the chief town in that neighbourhood. Cardia was the birthplace of Alexander's secretary
Eumenes and of the historian
Hieronymus.