The Aheloy ( bg, Ахелой) or Achelous ( el, Αχελώος) is a river in eastern

Bulgaria Bulgaria (; bg, България, Bǎlgariya), officially the Republic of Bulgaria,, ) is a country in Southeast Europe. It is situated on the eastern flank of the Balkans, and is bordered by Romania to the north, Serbia and North Macedon ...

. It originates in the

Aytos Aytos ( bg, Айтос ), sometimes written Aitos and Ajtos, is a town located in eastern Bulgaria some 30 kilometers from the Bulgarian Black Sea Coast and belonging to the administrative boundaries of Burgas Province. It is the administrative ...

Karnobat Karnobat ( bg, Карнобат ) is a town in the Burgas Province, Southeastern Bulgaria. It is the administrative centre of the homonymous Karnobat Municipality. According to the 2021 census, the town has a population of 16,483 inhabitants.htt ...

mountain, 1.5 kilometres from

Dryankovets Dryankovets is a village in the municipality of Aytos Municipality, in Burgas Province, in southeastern Bulgaria Bulgaria (; bg, България, Bǎlgariya), officially the Republic of Bulgaria,, ) is a country in Southeast Europe. It ...

, and flows directly into the

Black Sea The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, Roma ...

south of the village of

Aheloy Aheloy ( bg, Ахелой ) is a town and seaside resort in Pomorie Municipality of Burgas Province. it had 2,175 inhabitants. It is situated in eastern Bulgaria, on the Black Sea Coast between the major port of Burgas to the south and the bus ...

. The Aheloy River has a length of 39.9 kilometres and has an irrigation reservoir, the Aheloy Reservoir, built along its flow. The river's

drainage basin A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, t ...

covers 141 square kilometres and its average discharge is 0.7 cubic metres per second. The river is famous for being the site of the Battle of Achelous of 20 August 917 between Bulgarian ruler Simeon I and the Byzantines under Leo Phocas, one of the largest battles in the

Middle Ages In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire a ...

and one of the greatest military successes of the

First Bulgarian Empire The First Bulgarian Empire ( cu, блъгарьско цѣсарьствиѥ, blagarysko tsesarystviye; bg, Първо българско царство) was a medieval Bulgar- Slavic and later Bulgarian state that existed in Southeastern Europ ...

References

* Rivers of Bulgaria Landforms of Burgas Province Tributaries of the Black Sea {{Bulgaria-river-stub