Gregory “the theologian”, “the younger, was a rich, educated nobleman. His mother Nona was a devout Christian who brought her husband, Gregory of Nazianz the Elder, to the Christian faith. Gregor was born late. He studied in Caesarea in Cappadocia – today’s Kayseri -, in Caesarea in Palestine and in Alexandria, where he met Athanasius, as well as from about 348 rhetoric in Athens 1, where he met Basilius, with whom he had a lifelong intimate friendship from then on, here he also met the later emperor and Persecutor Julian Apostata, whose return he then criticized in 364 in two preserved orationes, speeches and whose misdeeds he predicted.
Joachim Schäfer: Article Gregor von Nazianz (“the Younger”), from the Ecumenical Dictionary of Saints: https://www.heiligenlexikon.de/BiographienG/Gregor_von_Nazianz_der_Juengere.htm