The poverty and lack of work on the island forced him despite the objections of his mother to travel to Rhodes, to work towards securing the future and to help his home.
He was honest and hardworking, and because of this everyone loved him. Some friends introduced him to the Turkish governor of Rhodes Hassan Kapitan, who gave him a job in his seraglio. He groomed Hasan Bey’s horse and did various other jobs always willingly.
At a great gathering Constantine got drunk and Hassan Kapitan asked the Hodjas to have a sounneti, in other words to circumcise him, and put on him the white turban, giving him the name of the governor, Hassan. When he woke up the next morning he realized what had happened, but it was difficult to react immediately. His concern grew when, having sent his mother money with someone, she heard that he had changed his faith, and in utter bitterness she threw away the money, locked her house and cried day and night, inconsolable for what happened to her child.
In Rhodes again all his friends distanced themselves from him and was sorry, because they saw him as a Janissary.
He went to Hydra to see his mother and as he approached his family home he asked for a drink of water from a woman of the neighborhood which she gave him, but as soon as she stepped away from him she broke the container that touched his lips. Arriving at the house he knocked on the door and to his mother’s question as to who it was he replied, “I am your son Hasan who has arrived from Rhodes”. With a voice twisted in pain she replied: “I’m not opening to you. I don’t have any son Hassan. I only have a son Constantine.”
Only God knows the sorrow and pain of the young man from Hydra. Without losing time he returned to Rhodes and directly went to Rodini where in a cave an Elder Spiritual father lived in asceticism. Kneeling in front of his feet he confessed his sin and the Spiritual father gave him forgiveness and the appropriate advice on what he should do thereafter.
He threw away the turban and Turkish clothes and taking a boat he first went to Crimea and then to Constantinople, where the holy Ethnomartyr Patriarch Gregory V advised him to go to Mount Athos and stay there forever.
Having remained in the Monastery of the Iveron living with a lot of repentance, prayer and ascesis and having taken the Monastic schema, with the permission of his Spiritual father he returned to Rhodes with the firm decision to go to Hassan Capitan and tell him that he was a Christian and a Christian he would die.
The blessed hour arrived. He went in front of his former boss, the terrible governor of Rhodes, Hassan. With faith and indescribable courage he said: "Hassan Bey I am your servant Constantine from Hydra who you fraudulently made a Muslim. I return you your false religion and tell you that I am a Christian and a Christian I will die.” Hassan was in a daze. Seeing Constantine throwing the muslim turban to the flies he was incredibly angry and rushed at Constantine hitting him with fists and kicks. In the palace of the Knights was a dark basement which was called the prison of Zyntantou. Zintani in Turkish means darkness. There they began to terribly torture him day and night. In the end they tied him to a tree trunk putting his feet in two holes. He endured all with unceasing prayer. One night the jail shinned with a heavenly light and his feet were freed from the locks. Turkish and Christian prisoners admired him. After five months they brought him again before the Turkish commander and having the same faith and courage he again confessed the Christian faith and was returned to prison and on November 14th, 1800 on the orders of the Sultan he suffered a martyr's death by hanging, which according to some took place at Kolona, and according to others at Mandraki. He kissed his small cross and prayed and when the executioner went to get Constantine he threw him on a plane tree, that he not fall into profane hands. Constantine was 30 years old when he was hung on the plane tree. And Turks and Christians relate that that night when Constantine was martyred a great bright cross shone with its light on the plane tree. The next year a strong tornado tore down the plane tree and after a short time the commander Hassan Bey died from a bad illness.
The then Bishop of Rhodes Agapios and the elders of Rhodes sought the holy relic and buried it with great honors behind the holy Church of the Entrance of the Theotokos in Niochori. Later the marble plaque that was placed above the Saint’s grave by his fellow countryman Constantine Kafas was uncovered and today is in the wall of the same church
"This is the tomb of the Holy Neomartyr Constantine Nydriotis, placed by Constantine of Hydra Kafa.”
(taken from the full service of the Saint in Greek available here: http://www.imr.gr/konstantinosakolouthia.htm)