Thracian Mesembria (6th–1st c. BC)
The settlement was founded around 510 BC by Dorian colonists from Megara on the site of an earlier Thracian post; by 494 BC they were joined by settlers from Chalcedon and Byzantium. The original Thracian name was Melsambria — after the Thracian leader Melsa and the suffix '-bria' (Thracian for 'town') — later Hellenised to Mesambria. Fortification walls and terracotta finds in the Archaeological Museum date from this period.
Roman period (1st c. BC – 4th c. AD)
Once part of the Roman Empire, Mesembria became a lively port — it minted its own coins and expanded its trade. Roman baths and sections of the fortress wall survive from that era.
Byzantium & mediaeval Bulgaria (5th–14th c.)
The town passed in turn between Byzantium and the First and Second Bulgarian Empires, changing rulers several times. In autumn 812, after a two-week siege, Khan Krum captured Mesambria, and among the spoils was a vessel of 'Greek fire'. Prince Boris I returned it to Byzantium in 864, and later Tsar Simeon the Great conquered it again. Many of the churches were built during this era: St Sophia (the Old Metropolitan Church), Christ Pantocrator, St John Aliturgetos and others.
Ottoman era and National Revival (1453–1878)
Under Ottoman rule, Nessebar retained its status as a Christian metropolitan town. In the 18th–19th centuries, the characteristic Revival-era timber-framed houses were built; some still function today as museums, hotels and restaurants.
Liberation and UNESCO (1878 — today)
After the 1878 Liberation, Nessebar became a Bulgarian fishing town. In 1956, the old town was declared an architectural and archaeological reserve, and in 1983 it was inscribed on the UNESCO World Heritage List. Today it is one of the most visited destinations on the Bulgarian Black Sea coast.