Antiquity (6th c. BC – 7th c.)
Thracians settled in the area of today's Aheloy from the 6th century BC. Later it was a small harbour used by the Greek colonies of Apollonia and Mesembria. The name "Aheloy" comes from the Greek "Acheloos" — a river deity meaning "the river".
The Battle of Aheloy (917)
On 20 August 917, one of the greatest battles in mediaeval Bulgarian history was fought near the river mouth. Tsar Simeon I the Great crushed the Byzantine army of Leo Phocas — over 20,000 Byzantines killed. The victory cemented Bulgarian dominance in the Balkans and is described by Byzantine historians as "catastrophic".
Middle Ages and Ottoman Empire (10th–19th c.)
After the great battle, the site kept strategic significance — a border between the Bulgarian Empire and Byzantium until the 14th century. Under Ottoman rule, Aheloy was a small fishing village with Greek and Bulgarian inhabitants, about 30 houses. In the 19th century, refugees from Eastern Thrace and Asia Minor settled here.
Modern Aheloy (1878 — today)
After the 1878 Liberation, Aheloy remained in Eastern Rumelia and joined the Principality of Bulgaria in 1885. During the socialist period it gained resort status with small holiday stations. In 1984 Aheloy was declared a town. Today it is a quiet family alternative to the mass resorts, drawing mostly Bulgarian and Romanian tourists.