Conversion of Gregory the Elder
Nonna's most celebrated act in the tradition is the conversion of her husband. Gregory the Elder had belonged to the Hypsistarians — a sect that combined monotheistic veneration of the 'Most High' (Hypsistos) with Jewish observance and elements of fire worship. According to the account transmitted through their son Gregory the Theologian, Nonna brought about her husband's conversion through sustained prayer and fasting. Gregory the Elder went on to be baptized, ordained, and made Bishop of Nazianzus, serving in that role for many years alongside his wife.
Gregory the Theologian wrote warmly of his mother as the driving spiritual force of the household, crediting her with laying the foundation for his own theological formation.