He was a holy hermit in Bithynia, in the fifth age.  In his youth he was one of the equestrian guards of Theodosius the Younger; but this state of life, which he discharged with the utmost fidelity to his prince, did not hinder him from making the service of God his main concern.  All his spare time was spent in solitude and prayer; and he often visited holy hermits, to spend the nights with them in tears and singing the divine praises, prostrate on the ground.  The fear of vain-glory moved him to retire to the desert mountain of Oxea, in Bithynia, eight miles from Constantinople.  After the council of Chalcedon, where he appeared upon summons by order of the emperor Marcian, against Eutyches, he chose a cell on the mountain of Siope, near Chalcedon, in which he contributed to the sanctification of many who resorted to him for advice; he finished his martyrdom of penance, together with his life, about 470.  Sozomen commended exceedingly his sanctity whilst he was yet living.  Saint Stephen the Younger caused the church of his monastery to be dedicated to God, under the invocation of our saint; and mount Siope is called to this day Mount Saint Auxentius.  See his life, written from the relation of his disciple Vendimian, with the remarks of Henschenius.