This tradition enjoyed a general acceptance until the early 20th century. The Jewish origin, let alone the biblical descent, of the Bagratids has been discounted by modern scholarship. Cyril Toumanoff's research concluded that the Georgian Bagratids branched out of the Armenian Bagratid dynasty in the person of Adarnase, whose father Vasak (son of Ashot III the Blind, presiding prince of Armenia from 732 to 748) passed to Kartli following an abortive uprising against Arab rule in 775. Adarnase’s son, Ashot I, acquired the Principality of Iberia in 813 and thus founded the last royal house of Georgia. Accordingly, the legend of the Davidic origin of the Georgian Bagratids was a further development of the earlier claim entertained by the Armenian dynasty, as given in the work of the Armenian author Moses of Khorene. Once the Georgian branch, which had quickly acculturated in the new environment, assumed the royal power, the myth of their biblical origin helped to maintain their legitimacy and became a major ideological pillar of their millennium-long rule of Georgia.