Proclus, Archbishop of Constantinople

Reading from the Synaxarion:

Saint Proclus lived during the reign of Saint Theodosius the Younger. A
disciple and scribe of Saint John Chrysostom, he was ordained Bishop of
Cyzicus about the year 426, but because the people there unlawfully
elected another bishop before his arrival, he remained in Constantinople.
In 429, Nestorius, who had been Archbishop of Constantinople for
about a year, and had already begun his blasphemous teaching that it is
wrong to call the holy Virgin "Theotokos," invited Bishop Proclus to
give a sermon on one of the feasts of our Lady, which he did, openly
defending in Nestorius' presence the name "Theotokos," that is, "Mother of
God." Saint Proclus was elevated to the throne of Archbishop of
Constantinople in 434. It was he who persuaded Emperor Theodosius the Younger
and his holy sister Pulcheria to have the most sacred relics of his
godly teacher Saint John Chrysostom brought back from Comana, and
triumphantly received them upon their return to the imperial city (see Jan. 27
and Nov. 13). He reposed in peace in 447.

Kontakion in the Fourth Tone
On this day, thy ven'rable departure from us, O wise Proclus blest
of God, is celebrated fittingly with joy by her that in very truth
is the most honoured of cities in all the world.