Antiquity and Byzantium (5th c. BC – 14th c.)
Agathopolis was founded in the 5th century BC by Greek colonists from Apollonia Pontica. During the Roman Empire it flourished as a port and trading centre; later it became an important Byzantine fortress on the eastern frontier. In 1306 Emperor Michael IX reinforced its walls, parts of which survive to this day.
Ottoman period and Bulgarian Revival (1453 – 1878)
After the fall of Constantinople in 1453 the town came under Ottoman rule but kept its Greek character — population mostly Greek, seat of a small bishopric. In the 18th–19th centuries it grew as a fishing and trading hub; the Ascension Church was built in 1776 and the Greek School followed in 1873.
Bulgarian Ahtopol (1913 — today)
After the Balkan Wars (1912–1913) Ahtopol became part of Bulgaria. A great fire in 1918 destroyed much of the old Revival-era architecture. After the 1925 population exchange the Greek inhabitants left for Greece and their place was taken by Bulgarian refugees from Eastern Thrace. Today Ahtopol is a small fishing town and summer destination, hosting satellite days of the Apollonia festival and serving as a gateway to the Strandzha mountains.