The modern city of Pomorie is located on a narrow peninsula of the same name, extending 3.5 km into the Black Sea, on the northwest coast of the Burgas Bay.

The sea coast is low, sandy, with an open horizon to the east and west, protected to the north by Stara Planina.

In 1934 the town was renamed to Pomorie, from the Bulgarian "po-" (in this context "by, next to") and "more" ("sea"), corresponding to one of the two etymologies of the original Greek name.

Possibly founded in the 5th or 4th century BC as a colony of Apollonia (today Sozopol), Anchialos was mentioned in Strabo's Geographica as a small town.

It was briefly captured by Messembria (Nesebar) in the 2nd century BC, but reconquered by Apollonia and its fortified walls destroyed.

The western Black Sea coast was ultimately conquered by the Romans under Marcus Licinius Crassus in 29-28 BC after continuous campaigns in the area since 72-71.

As the Odrysian kingdom's self-independence was abolished in 45 AD, Anchialos became part of the Roman province of Thrace and was formally proclaimed a city under Emperor Trajan.

However, the invasion of barbarian tribes from the north meant an end to this prosperity in the middle of the 3rd century, with the Goths briefly capturing Anchialos around 270.

His and Constantine the Great's reforms restored the city's prosperity for a while, as the proximity to the new capital of Constantinople made Anchialos a key food supply centre.

A high-ranking Byzantine general named Vitalian in 513 revolted in the region and briefly took control of Anchialos and the neighbouring cities to use their fleet in his attack of Constantinople until he was crushed in 515.

However, the Notitiae Episcopatuum of Pseudo-Epiphanius, written in the reign of Byzantine Emperor Heraclius (c. 640), gives it as an autocephalous archbishopric, today listed by the Catholic Church as a titular see.

After the restoration of the Bulgarian state Anchialos changed hands several times until it was captured by the Venetian knights of Amadeus VI, Count of Savoy in October 1366.

At the outbreak of the Greek War of Independence (1821) a part of the town's representatives, priests as well as the Orthodox bishop Eugenios were executed by the Ottoman authorities.

After the Russian forces withdrew the whole of what is today Eastern Bulgaria gradually depopulated, with many people fleeing to the Christian lands to the north.

[11] Anchialos was liberated from Ottoman rule on 27 January 1878 and became part of Eastern Rumelia as a kaza centre in Burgaz sanjak until Bulgaria unified in 1885.

[13] The town accommodated many Bulgarian refugees from Eastern Thrace, mainly from around Lozengrad after World War I, who replaced the Greeks who had fled in the first decade of the 20th century; in 1906 they founded Nea Anchialos in Greece.

During the 19th and 20th century it gradually lost most of its importance in the southern Bulgarian Black Sea Coast at the expense of rapidly developing Burgas.