Никифор I
Symbatios was the eldest son of the emperor Leo V the Armenian () and his wife, Theodosia. His father was an Armenian commander in Byzantine service, possibly descended from the Gnuni family. He had risen to high command as a protégé of Bardanes Tourkos, but deserted him when the latter rebelled against Nikephoros I (). His mother was also of Armenian origin, the daughter of the "patrikios" Arsaber who attempted an unsuccessful usurpation against Nikephoros I in 808. As he was a child at the time of his father's accession to the throne, Symbatios was born sometime between 800 and 810. Michael I Rhangabes (), the son-in-law and successor of Nikephoros I, was likely the boy's godfather.