At the death of his father in 876, he inherited the Duchy of Lower Tao and was recognized as legitimate ruler of Iberia by the Byzantine Empire, which granted him the title of Kouropalates.
[2] In 881, northern Georgian nobleman Guram Mamphali ceded his domains in Trialeti to the powerful Liparit Baghvashi, a prince under David I's suzerainty.
An Armenian-Abbasid coalition, reinforced by troops loyal to the Bagrationi dynasty, intervened and expelled Nasra to the Byzantine Empire.
However, his young age led Byzantium to appoint David's cousin Gurgen as Kouropalates in Iberia, which would lead to a civil war that ended in 888 with the crowning of Adarnase as the "king of the Iberians".
This lineage cannot be confirmed by Georgian sources and it may be an anachronism confusing with his own daughter, who married another Adarnase (David I himself being the grandson of Smbat VIII Bagratuni).