Krum's campaigns Simeon I's campaigns Sviatoslav's invasion of Bulgaria Byzantine conquest of Bulgaria Uprising of Peter Delyan Second Bulgarian Empire The Battle of Anchialus (Bulgarian: Битката при Анхиало) (Medieval Greek: Μάχη του Αγχίαλου) occurred in 708 near the modern-day town of Pomorie, Bulgaria In 705, the Bulgarian Khan, Tervel helped the ex-emperor of Byzantium, Justinian II, regain his throne after 10 years in exile.

To show his gratitude, Justinian gave the Bulgarians an enormous quantity of gold, silver, and silk, as well as the "Zagore" area, located between Stara Zagora, Sliven, and the Black Sea.

Three years later, Justinian II considered himself strong enough to invade Bulgaria and restore his rule over these lands.

The Byzantines reached the Anchialus fortress and set their camp there, unaware of the fact that the Bulgarian army was in the vicinity.

While the invaders were gathering food, Tervel and his cavalry charged the outermost Byzantine troops, while at the same time the infantry attacked the camp.