Kontakion in the Third Tone Clad, O godly-minded one, with an invincible armor, thou didst dash to pieces the pride of the Western rebellion; thou wast brought forth as the champion of Orthodoxy, as the Comforter's own instrument and pure vessel. For this cause, to thee we cry out: Rejoice, O Mark, thou boast of the Orthodox flock.

Mark, Bishop of Ephesus

Reading from the Synaxarion:

The great teacher and invincible defender of the One, Holy, Catholic,
and Apostolic Church, Saint Mark, was the offspring and scion of the
imperial city, Constantinople. Reared by most pious parents, and
instructed in secular and spiritual wisdom, he became preeminent in both.
Saint Mark lived as an ascetic on the Prince's Islands and later in the
monastery of Saint George Magana in Constantinople. He passed through all
the degrees of the priesthood, and was finally advanced to the
dignity of Archbishop and the lofty throne of the Metropolis of Ephesus.
At the insistence of Emperor John Paleologos, the Saint was sent to
the council of the Latins in Florence, to unite the churches that had
been divided for so many years. He astounded the papal teachers with
the divine wisdom of his words, and was the only one who did not sign
the blasphemous decree of that false council. Because of this, the
Holy Church of Christ has ever honored this great man as a benefactor,
teacher, sole defender, and invincible champion of the Apostolic
Confession. He reposed in 1443.

Kontakion in the Third Tone
Clad, O godly-minded one, with an invincible armor, thou didst dash to
pieces the pride of the Western rebellion; thou wast brought forth as
the champion of Orthodoxy, as the Comforter's own instrument and pure
vessel. For this cause, to thee we cry out: Rejoice, O Mark, thou boast
of the Orthodox flock.