Sozopol is one of the oldest towns on Bulgarian Thrace's Black Sea coast. The first settlement on the site dates back to the Bronze Age. Undersea explorations in the region of the port reveal relics of dwellings, ceramic pottery, stone and bone tools from that era. Many anchors from the second and first millennium BC have been discovered in the town's bay, a proof of active shipping since ancient times.
The town was founded in the 7th century BC by Greek colonists from Miletus as Antheia (Ancient Greek: Ἄνθεια). The town established itself as a trade and naval centre in the following centuries and became one of the largest and richest Greek colonies in the Black Sea region. Its trade influence in the Thracian territories was based on a treaty dating from the fifth century BC with the Odrysian kingdom, the most powerful Thracian state. Apollonia became a legendary trading rival of another Greek colony, Mesembria, today's Nessebar.
