The First Battle of Constantinople

Emperor Justinian II Rhinotmetos sought Khan Tervel's help to regain the Byzantine throne. Tervel agreed in return for gifts and the emperor's daughter in marriage.

The battle ended successfully for the Bulgarian army, and Justinian returned to power. He rewarded the Bulgarians with silk, gold and silver, bestowed the high Byzantine title of caesar on Kan Tervel and erected a statue of him in Constantinople.
According to some chroniclers, Tervel also received Zagore in return for his assistance, extending the young Bulgarian state's territory into modern southern Bulgaria, south of the Balkan Mountains.