Born on the island of Crete to Christian parents, Saint Hilarion, in holy baptism John, preserved piety from his youth. After ten years with his uncle in Constantinople, he began to serve a merchant from Chios named Francesco. Accused of theft, John, falling into despair, turned to the mother of the Sultan and, succumbing to temptation, accepted the Muslim faith. However, after three days, realizing his error, he repented and left the palace, returning to his spiritual father, Hieromonk Simeon.
After long sufferings and searches, John decided to return to Constantinople to confess the Christian faith and accept a martyr's end. He went to the Holy Mount Athos, where he took monastic vows under the name Hilarion. Deepening in asceticism, he sought martyrdom, despite the warnings of the elders.
Having received a blessing, Hilarion returned to Constantinople, where, enduring sufferings, he boldly confessed his faith before the Bash-aga and other tormentors. After cruel tortures, he was sentenced to death. At the place of execution, the saint knelt down and, reading the symbol of faith, accepted a martyr's death on September 20, 1804.
The body of the saint was ransomed by Christians and buried with honors on the island of Proti. The relics of Saint Hilarion became renowned for miracles, healing the afflicted and manifesting signs. His memory is honored for steadfastness in faith and martyrdom for Christ.