Dulo clan
Kurt (Kubrat; c. 632–665), a member of the clan, revolted against the Pannonian Avars and founded the Old Great Bulgaria on the territory of modern Ukraine. During the second half of the 7th century his sons split up the Bulgar royal family and spread over Europe, from the Volga river to the shadow of Matese mountains: Bezmer (Ukraine), Kotrag (Volga Bulgaria), Kuber (Balkan Macedonia), Asparukh (Danube Bulgaria) and Alcek (Sepino, Bojano, Isernia). In the "Nominalia" the Bezmer (c. 665–668) was the last Dulo ruler on the northern side of Danube river (of the Old Great Bulgaria), while the Asparukh (c. 681–701) was the first from the southern side of the river (First Bulgarian Empire). He was followed by Tervel (c. 700–721), and the last ruler of Bulgaria from the Dulo clan, Sevar (c. 721–737). According to Theophanes, in 761 or 762 the Bulgars "rose up, killed their hereditary lords and set up as their king an evil-minded man called Teletzes, who was 30 years old". Historians usually interpreted the testimony as evidence of a massacre of the previous dynasty (the Dulo clan), and the rise of a new leader with no connection to the previous regime.