Dulo clan
The First Bulgarian Empire (681–1018) had a significant political influence in the Balkans. In the time of Tervel (700–721) the Bulgars helped Byzantines two times, in 705 the Emperor Justinian II to regain his throne, and 717–718 defeating the Arabs during the siege of Constantinople. Sevar (738–753) was the last ruler from the Dulo clan, and the period until c. 768-772 was characterized by the Byzantino-Bulgar conflict and internal crisis. In the short period followed seven rulers from the Uokil and Ugain clan. Telerig (768–777) managed to establish a pacific policy with Byzantium, and restore imperial power.