Cabyle used to be one of the most important centers of south-eastern Thrace. It was established around 2000 BC on the Zaychi Vrah Heights. In 341 BC Cabyle was conquered by the army of Philip II of Macedon and was later included in the Empire of Alexander of Macedon. It was colonised by Philip with rebellious Macedonians. In the 3rd century BC it was governed again by the Thracians. The town was a major trade and military center between the 3rd and the 2nd centuries BC. The town is noted by numerous ancient authors including Demosthenes, Polybius, Strabo, Pliny the Elder, and Stephanus of Byzantium.
Source: Wikipedia
