Alexis was the only son of a rich and distinguished Roman senator named Euphemianus, and his wife, Agalais. They set a high standard of godly living: his father, though wealthy, sat down to dine only once a day, at sunset.
From his Christian parents, he learned to be charitable to the poor. Alexis wanted to give up his wealth and honors but his parents had chosen a rich bride for him. Because it was their will, he married her.
Yet right on his wedding day, he obtained her permission to leave her for God. Then, in disguise, he traveled to Edessa (Odessa) in Syria (Mesopotamia) and lived in great poverty near a Church of Our Lady. There, during the episcopate of Bishop Rabula (412-435), he lived as a poor beggar, soliciting alms at the church door. These he divided among the rest of the poor, after reserving barely enough for the absolute necessities of life.
One day, after seventeen years, a picture of our Blessed Mother spoke to tell the people that this beggar was very holy. She called him "The man of God." He fled the resulting fame, fled the city and took ship for Laodicea. By divine providence, the ship was blown off course and forced to land in Rome.
Taking this as a sign, Alexis, still disguised as a beggar, returned to his parents' house, where he sat at the gates, unrecognized by any of his family. His father, not knowing who he was, allowed him to live in a hut in his courtyard. There Alexis spent another seventeen years, living only on bread and water. He died clutching a piece of paper on which he had revealed his true identity. At the time of his death, the pope of Rome heard a voice saying "Look for the Man of God," and revealing where he should look. It is said that the Emperor, the Pope and a large retinue came to the house, where they found Alexis dead in his tiny hut, his face shining like the sun. His parents and wife were at first overcome with grief to learn that their son and husband had been secretly living near them, but they were comforted when they saw that his body healed the sick and exuded a fragrant myrrh. Thus they knew that God had glorified him. His head is preserved at the Church of St Laurus on the Peloponnese.
(Some relations of his life state he lived in a corner under the stairs of his parents' house. That he used to go out only to pray in church and to teach little children about God. That after Alexis died was buried in the common grave of the poor, but before his death, he had revealed his true identity to one of the church servants. After the Saint's death, the servant told this to the Bishop. The grave was opened, but only his pauper's rags were found, and in them a note which stated who he was and how he had lived his life of penance from the day of his wedding until death, for the love of God. He was honoured as a saint and his father's house was converted into a church placed under the patronage of Alexius.)
He appears in connection with St. Boniface as titular saint of a church on the Aventine at Rome. On the site now occupied by the church of Sant' Alessio there was at one time a diaconia, i.e. an establishment for the care of the poor of the Roman Church. Connected with this was a church which by the eighth century had been in existence for some time and was dedicated to St. Boniface. In 972 Pope Benedict VII transferred the almost abandoned church to the exiled Greek metropolitan, Sergius of Damascus. The latter erected beside the church a monastery for Greek and Latin monks, soon made famous for the austere life of its inmates. To the name of St. Boniface was now added that of St. Alexius as titular saint of the church and monastery. Among the frescoes executed towards the end of the eleventh century in the Roman basilica of St. Clement (now the lower church of San Clemente) are very interesting representations of events in the life of St. Alexius. The church of Sts. Alexius and Boniface on the Aventine has been renovated in modern times but several medieval monuments are still preserved there. Among them may be the shed/stairs.