The Orthodox Church honors the memory of Saint Martyr Pamphilus and Saint Flavian, Patriarch of Constantinople today.
Saint Flavian, who lived in the 5th century AD, initially served as a presbyter and skeuophylax (keeper of the vessels) of the Hagia Sophia. In 447 AD, he succeeded Saint Proclus on the patriarchal throne and was known for his moral integrity, virtue, and dedication to the Orthodox Faith.
Just a year into his patriarchate, Saint Flavian presided over a local council in Constantinople where he condemned the teachings of monophysitist Archimandrite Eftychis. Eftychis propagated the belief that Christ only had one nature, the divine nature, as the human nature was entirely absorbed by the divine.
Saint Flavian faced persecution and torture for his unwavering commitment to the Orthodox faith during the Robber Council of 449 AD, also known as the Latrocinium. This council, led by Archimandrite Eftychis and supported by Dioscurus of Alexandria, aimed to challenge Orthodox doctrine.
After the council, Saint Flavian passed away, becoming a martyr for his steadfastness in the Orthodox faith.
Source: Church of Cyprus