Saint John Mavropous, Bishop of Euchaita, hymnographer and teacher of Constantinople.
John Mavropous was one of the most learned men of eleventh-century Constantinople, teacher of Michael Psellos and a counsellor of the emperor Constantine IX Monomachos. He was later consecrated Metropolitan of Euchaita in Pontus.
He composed many canons and hymns still in use, and tradition credits him with establishing the common feast of the Three Hierarchs on January 30.
Feast day
On the New Calendar, John Mavropous of Euchaita is commemorated on October 5. Churches on the Old (Julian) Calendar keep the feast on October 18 of the civil calendar.
Also commemorated on October 5

Methodia of Kimolos
Holy Woman, Μεθοδία
Venerable Methodia of Kimolos, the recluse and spiritual mother of the Cyclades.
Name days: Methodia
Hermogenes the Hieromartyr
Hierarch, Ερμογένης
Holy Hieromartyr Hermogenes the Wonderworker.
Name days: Ermogenis, Hermogenes, Ermogenes
Mamelchtha of Persia
Holy Woman, Μαμέλχθα
Holy Martyr Mamelchtha of Persia, a former priestess of Artemis who was stoned for Christ.
Eudokimos of Vatopedi
Venerable, Ευδόκιμος ο Βατοπεδινός
Venerable Eudokimos the Newly-Revealed of Vatopedi Monastery on Mount Athos.