St. Nerses the Great was the great-grandson of St. [[Gregory the Enlightener|Gregory the Illuminator]]. He spent his youth in Caesarea in Cappadocia, there marrying Sandukht, a member of the prominent Mamikonian family. (Together the Saint and Sandukht had a son, St. [[Isaac the Great|Sahag]].) After the death of his wife he became a courtier of King Arshak of Armenia, a few years after this being elected Catholicos of Echmiadzin and All the Armenians (in 353). Both his father and his uncle, Bab, were passed over by the hierarchy because of their worldliness and weak faith. St. Nerses rejected his election as catholicos, but at Arshak's insistence he was nonetheless ordained a deacon and priest and then consecrated to the episcopate by Archbishop
[[Eusebius of Caesarea ]] in Cappadocia.
During St. Nerses' catholicate the Orthodox Faith went from being primarily that of the royal family and the aristocracy to being the faith of the entire Armenian nation, thanks in large part to the efforts of missionary monks he sent out to more thoroughly evangelize the countryside. He also enacted important ecclesiastical reforms, at the Council of Ashtishat promulgating canons regulating marriage, fasting, and the divine services. St. Nerses was responsible for the opening of a number of schools, hospitals, and orphanages in Armenia.