Khan Tervel's Battle with the Arabs

In the autumn of 717, a large Arab army besieged the Byzantine capital, Constantinople. Emperor Leo III appealed to Khan Tervel for assistance. The Bulgarian ruler judged with foresight that the Arab threat was far more dangerous than the Byzantine one and responded despite the two countries' longstanding hostility. He personally led Bulgarian forces towards Constantinople and attacked the Arabs on land in coordination with the Byzantine fleet. The Bulgarian units imposed a complete blockade on the Arab forces, condemning them to starvation during the approaching winter. When spring came, the few survivors attempted to break through the Bulgarian blockade, but Tervel's cavalry swept them away. On 15 August 718, the Arabs abandoned the siege and fled Constantinople by sea.

The battle ended in success for the Bulgarian state. Through his victory, Khan Tervel saved not only Byzantium from certain destruction, but also all of Europe from an inevitable Arab invasion.