Thrax was a child of Ares by an unknown mother.

The ancient Thracians were a group of war-like tribes that inhabited the Eastern, Central and Southern part of the Balkan peninsula, as well as the adjacent parts of Eastern Europe.

By Strabo's time, "Thrace as a whole consists of twenty-two tribes. But although it has been devastated to an exceptional degree, it can send into the field fifteen thousand cavalry and also two hundred thousand infantry." (Geography 7 f47)

In the 8th century B.C. the Greek colonies of the Thracian coasts were founded by Greeks from the islands of the Eastern aegean and from the Ionian city-states of Northern Greece. Between the mouth of the Nestos River and the Abdera, Dikaia, Strymi, Maroneia, Orthagoria, Mesimvria-Zoni, Drys, and Sali were founded. On the Western coast of the Black Sea the Milesians founded Apollonia, Odessos, Tomi, and Kallati, while the Megarians founded Mesimvria.