He took up the monastic life when very young, and lived as a recluse for many years, and gained the grace to heal sicknesses and drive out demons by his prayers. Later he became abbot of the Monastery of Pelekete in Bithynia. During the reign of the Emperor Leo the Isaurian, he and his monastery steadfastly upheld the holy icons, and were fiercely persecuted. Hilarion and his forty monks were exiled to a prison near Ephesus, where the Saint reposed.