Saint Alexander
Saint Alexander led the church of the imperial city in the 4th century. According to the historian Gelasius of Cyzicus, his aged and infirm predecessor Metrophanes sent Alexander in his place to the First Ecumenical Council at Nicaea in 325 and designated him as his successor. Alexander served as bishop of the city through the period in which it was refounded as Constantinople, and the OCA's account dates his tenure as patriarch to roughly 325-340.
Alexander is best remembered for his firm stand against Arius. At the Council of Nicaea he supported the Trinitarian confession against the Arian teaching. When the Emperor Constantine afterward commanded that Arius be received back into communion, Alexander refused, persuaded that Arius's repentance was not sincere, and would not yield despite threats. The tradition relates that he shut himself up in fervent prayer that God would take him from this world rather than force him to restore Arius; Arius died before he could be received into the Church. Sources differ on the precise dates of Alexander's birth and death, placing his birth somewhere in the third century and his repose in the late 330s; he is said to have reached a very advanced age.
Saint John the Faster
Saint John IV, known as 'the Faster' (Nesteutes) for his rigorous ascetic life and fasting, served as Patriarch of Constantinople in the 6th century. According to the OCA, his patriarchate fell in the years 582-595. Before his elevation he had served the church in lesser orders and was noted for his ascetical discipline and his charity to the poor.
He is remembered in the Orthodox tradition as the compiler of a penitential Nomokanon, a rule governing penances. The instructions he gave for the guidance of priests came down in several distinct versions that nonetheless share a common foundation, and they shaped later penitential practice in the Church.
Saint Paul the New
Saint Paul, called 'the New,' was a Patriarch of Constantinople in the 8th century, during the iconoclast controversy. Born in Cyprus, he came to the patriarchal throne in the period of the persecution of those who venerated the holy icons; the OCA places his tenure in the years 780-784 and notes that he had served under the iconoclast emperor Leo IV.
The tradition remembers Paul as virtuous and pious but timid: seeing the suffering that the Orthodox endured for the sake of the holy icons, he at first concealed his own Orthodox conviction. He afterward withdrew from his office and entered a monastery, and it was his retirement that opened the way for his successor and for the calling of the council that would restore the veneration of icons.