The battle of Anchialus occurred in 763, near the town of Pomorie

Pomorie

Pomorie is a town and seaside resort in southeastern Bulgaria, located on a narrow rocky peninsula in Burgas Bay on the southern Bulgarian Black Sea Coast. It is situated in Burgas Province, 20 km away from the city of Burgas and 18 km from the Sunny Beach resort. The ultrasaline lagoon...

 on the Bulgarian Black Sea Coast

Bulgarian Black Sea Coast

The Bulgarian Black Sea Coast covers the entire eastern bound of Bulgaria stretching from the Romanian Black Sea resorts in the north to European Turkey in the south, along 378 km of coastline. White and golden sandy beaches occupy approximately 130 km of the 378 km long coast...

 42°33′N 27°39′E. The result was a Byzantine victory.

Origins of the conflict

After the success in the battle of the Rishki Pass

Battle of the Rishki Pass

The Battle of the Rishki Pass took place in the pass of the same name, in Stara Planina, Bulgaria in 759. It was fought between the Bulgarian Empire and the Byzantine Empire...

 (759) the Bulgarian

Bulgarians

The Bulgarians are a South Slavic nation and ethnic group native to Bulgaria and neighbouring regions. Emigration has resulted in immigrant communities in a number of other countries.-History and ethnogenesis:...

 Khan Vinekh

Vinekh of Bulgaria

Vinekh was ruler of Bulgaria in the mid-8th century.According to the Namelist of Bulgarian Rulers, Vinekh reigned for 7 years and was a member of the Uokil clan . According to the chronology developed by Moskov, Vinekh would have reigned 754–762...

 showed surprising inaction and desire for peace which cost him the throne and his life. The new ruler, Telets

Telets of Bulgaria

Telets was the ruler of Bulgaria from 762 to 765.According to the Namelist of Bulgarian Rulers, Telets reigned for 3 years "instead of another", and he was a member of the Ugain clan. This is corroborated by the Byzantine sources, which indicate that Telets replaced the legitimate rulers of...

, was a firm supporter for further military actions against the Byzantines

Byzantine Empire

The Byzantine Empire was the Eastern Roman Empire during the periods of Late Antiquity and the Middle Ages, centred on the capital of Constantinople. Known simply as the Roman Empire or Romania to its inhabitants and neighbours, the Empire was the direct continuation of the Ancient Roman State...

. With his heavy cavalry he looted the border regions of the Byzantine Empire

Byzantine Empire

The Byzantine Empire was the Eastern Roman Empire during the periods of Late Antiquity and the Middle Ages, centred on the capital of Constantinople. Known simply as the Roman Empire or Romania to its inhabitants and neighbours, the Empire was the direct continuation of the Ancient Roman State...

 and in 16 June 763, Constantine V came out of Constantinople

Constantinople

Constantinople was the capital of the Roman, Eastern Roman, Byzantine, Latin, and Ottoman Empires. Throughout most of the Middle Ages, Constantinople was Europe's largest and wealthiest city.-Names:...

 with a large army and a fleet of 800 ships, with 12 cavalrymen on each.

The battle

The energetic Bulgarian Khan barred the mountain passes and took advantageous positions on the heights near Anchialus but his self-confidence and impatience incited him to go down to the lowlands and charge the enemy. The battle started at 10 in the morning and lasted until sunset. It was long and bloody but in the end the Byzantines were victorious although they lost many soldiers, nobles and commanders. The Bulgarians also had heavy casualties and many were captured, while Telets managed to escape.

Aftermath

Constantine V entered his capital in triumph and then killed the prisoners. The fate of Telets was similar: two years later he was murdered because of the defeat. The Byzantines failed to use the strategic advantage which they had and the prolonged wars in the 8th century ended in 792 at the Marcelae

Battle of Marcelae

The Battle of Marcellae took place in 792 at Markeli, near the modern town of Karnobat in south eastern Bulgaria. It is not to be confused with the earlier battle at the same place.-Prelude:...

with a great Bulgarian victory and reestablishment of the treaty of 718.