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.

Saint Gregory who was from Irenopolis of the Decapolis of Asia Minor, was the son of Sergius and Mary. He became a monk as a young man, and after struggling for many years in virtue and prayer under obedience to a wise spiritual father, he was informed by revelation that it was the will of God for him to live, like the Patriarch Abraham, with no certain dwelling, moving from place to place. His journeyings took him to Ephesus, Constantinople, Corinth, Rome, Sicily, Thessalonica, and again to Constantinople, where, after many labours in defence of Orthodoxy against Iconoclasm, he reposed in peace in the first half of the ninth century. He had two disciples, one of whom was Saint Joseph the Hymnographer (see Apr. 3), who wrote the Menaion service for Saint Gregory, his father in Christ.

Saint Catherine, who was from Alexandria, was the daughter of Constas (or Cestus). She was an exceedingly beautiful maiden, most chaste, and illustrious in wealth, lineage, and learning. By her steadfast understanding, she utterly vanquished the passionate and unbridled soul of Maximinus, the tyrant of Alexandria; and by her eloquence, she stopped the mouths of the so-called philosophers who had been gathered to dispute with her. She was crowned with the crown of martyrdom in the year 305. Her holy relics were taken by Angels to the holy mountain of Sinai, where they were discovered many years later; the famous monastery of Saint Catherine was originally dedicated to the Holy Transfiguration of the Lord and the Burning Bush, but later was dedicated to Saint Catherine. According to the ancient usage, Saints Catherine and Mercurius were celebrated on the 24th of this month, whereas the holy Hieromartyrs Clement of Rome and Peter of Alexandria were celebrated on the 25th. The dates of the feasts of these Saints were interchanged at the request of the Church and Monastery of Mount Sinai, so that the festival of Saint Catherine, their patron, might be celebrated more festively together with the Apodosis of the Feast of the Entry of the Theotokos. The Slavic Churches, however, commemorate these Saints on their original dates.