Gregory of Nyssa in the context of "Tomus ad Antiochenos"

Gregory of Nazianzus (Greek: Γρηγόριος ὁ Ναζιανζηνός, romanized: Grēgorios ho Nazianzēnos; c. 329 – 25 January 390), also known as Gregory the Theologian or Gregory Nazianzen, was an early Roman Christian theologian and prelate who served as Archbishop of Constantinople from 380 to 381. He is widely considered the most accomplished rhetorical stylist of the patristic age. As a classically trained orator and philosopher, he infused Hellenism into the early Church, establishing the paradigm of Byzantine theologians and church officials.

Gregory made a significant impact on the shape of Trinitarian theology among both Greek and Latin-speaking theologians, and he is remembered as the "Trinitarian Theologian". Much of his theological work continues to influence modern theologians, especially in regard to the relationship among the three Persons of the Trinity. Along with the brothers Basil of Caesarea and Gregory of Nyssa, he is known as one of the Cappadocian Fathers.

Neoplatonism was a major influence on Christian theology throughout Late Antiquity and the Middle Ages in the East, and sometimes in the West as well. In the East, major Greek Fathers like Basil, Gregory of Nyssa and Gregory of Nazianzus were influenced by Platonism and Neoplatonism, but also Stoicism often leading towards asceticism and harsh treatment of the body, for example stylite asceticism. In the West, St. Augustine of Hippo was influenced by the early Neoplatonists Plotinus and Porphyry. Later on, in the East, the works of the Christian writer Pseudo-Dionysius the Areopagite, who was influenced by later Neoplatonists such as Proclus and Damascius, became a critical work on which Greek church fathers based their theology, like Maximus believing it was an original work of Dionysius the Areopagite.

Pulcheria (c.378-c.385) was the daughter of the emperor Theodosius I and his first wife Aelia Flaccilla.

She was born prior to her father becoming emperor in January 379, but died in childhood, shortly before her mother. In his consolatory oration on Pulcheria, Gregory of Nyssa described her as “a new-sprung blossom, with shining petals not yet lifted fully from the bud,” and vividly recalled how her death devastated the populace, indicating strong sympathy for the emperor’s family.

Nyssa (Ancient Greek: Νύσσα) was a town and bishopric in Cappadocia, Asia Minor. It is important in the history of Christianity due to being the see of the prominent 4th century bishop Gregory of Nyssa. Today, its name continues to be used as a titular see in the Eastern Orthodox Church and the Roman Catholic Church.

The Cappadocian Fathers, also traditionally known as the Three Cappadocians, were a trio of Byzantine Christian prelates, theologians and monks who helped shape both early Christianity and the monastic tradition. Basil the Great (330–379) was Bishop of Caesarea; Basil's younger brother Gregory of Nyssa (c. 335 – c. 395) was Bishop of Nyssa; and a close friend, Gregory of Nazianzus (329–390), became Patriarch of Constantinople. The Cappadocia region, in modern-day Turkey, was an early site of Christian activity. While these three men are typically discussed as the Cappadocians, Macrina, Basil and Gregory's sister, was significant in forming them theologically and in terms of their interpretation of how to live out Christian religious practice.

The Cappadocians advanced the development of early Christian theology, for example the doctrine of the Trinity, and are highly respected as saints in both Western and Eastern churches.