Sergius was born at Tella, and was a friend of Jacob Baradaeus.[1] He became a monk at the monastery of Hala, and was ordained a priest by the bishop John of Anazarbus.[2] As a monk, Sergius accepted the doctrine of tritheism,[3] and accompanied Jacob Baradaeus to Constantinople in 527.[4] At Constantinople, Sergius tutored Empress Theodora's grandson Athanasius,[3] and became a friend of John Philoponus, who wrote a non-Chalcedonian treatise named "A Treatise Concerning the Whole and the Parts" at Sergius' request.[5]