St Alexander succeeded Metrophanes in the patriarchal see of Constantinople from 314 to 337 A.D.
During that period, just after the time of the persecutions had ended, the Church had another danger to confront: that of heresies. In those days, the heretical teachings of Arian were quite widespead. Arius taught that Jesus Christ was not consubstantial with the Father, but was simply created by the Father. In order to resolve any possible confusion and protect the truth, in 325 A.D. the First Ecumenical Council was summoned at Nicea of Asia Minor. The 318 Fathers that took part in that council, demonstrated the deceit of Arius and condemned him and his heretic doctrines.
Later, however, Arius convinced the emperor that he had repented. Then the emperor ordered the Patriarch Alexander that he would concelebrate the Divine Liturgy with Arius next Sunday. However, the Patriarch was rather doubtful about Arius' repentance and prayed that God would show the truth. And this happened in the following marvelous way:
«But Arius, as he was on his way to the church, was overcome by violent stomach pains near the column in the forum and entered a public lavatory. There he was rent apart and disgorged all his inside from below, undergoing the disembowelling of Judas for an equal betrayal of the Word, and having torn away the Son of God from the Father’s essence, he was torn apart and found dead. And so the Church of God was delivered from his mischief.» (from the additional note of the Synaxarion read during the Sunday of the Fathers of the First Ecumenical Council).
Information from the Synaxarion mention that Alexander was originally from Calabria in Italy and his parents were George and Vryaine. From very young he was given to God and stayed in a Monastery, where he cultivated virtue and became a good labourer of God's commands. He was granted divine visions, while for twenty days he stayed completely fasting. But he also stayed naked for four years and fell into thousands of problems because of attacks of the Saracenes. In this way, he lived many years, and travelling around Greece with his pupils Vitalios and Nikiphoros, he rested peaceful in the Lord.
His holy memory is kept on the 30th of August, second day from the end of the ecclesiastical year.