The Monk Peter of Athos, a Greek by birth, served as a voivode in the imperial troops and lived in Constantinople. In 667, during the war with the Syrians, St. Peter was captured and imprisoned in the fortress of the city of Samara on the Euphrates River. For a long time he languished in prison and reflected on what sins he had been punished by God for. Saint Peter remembered that he once had the intention to leave the world and enter a monastery, but never fulfilled it. He began to observe strict fasting in prison, prayed fervently and asked St. Nicholas the Wonderworker for intercession before God. 
St. Nicholas appeared to St. Peter in a dream and gave advice to call for the help of St. Simeon the God-receiver. Strengthening the prisoner in patience and hope, the saint appeared to him once more in a dream. For the third time, he appeared together with Saint Simeon the God-receiver in reality. Saint Simeon touched the chains of Saint Peter with his wand, and the iron melted like wax. The doors of the dungeon opened, and St. Peter was released. Saint Simeon the God-receiver became invisible, and Saint Nicholas escorted Saint Peter to the border of the Greek land. Recalling the vow, St. Nicholas also became invisible. To accept the monastic image at the tomb of the Apostle Peter, St. Peter went to Rome. St. Nicholas did not leave him without his help: he appeared to the Pope in a dream and told about the circumstances of St. Peter's release from captivity, instructing the pope to tonsure the former prisoner into monasticism.
The next day, in front of a crowded gathering of people during the divine service, the pope said loudly: "Peter, who came from the Greek land, whom St. Nicholas freed from prison in Samara, come to me." Saint Peter appeared before the pope, who tonsured him into monasticism at the tomb of the Apostle Peter. The Pope taught Saint Peter the rules of monastic life and kept the monk with him. Then, with a blessing, he released Saint Peter to wherever God would deign to direct him.
Saint Peter boarded a ship sailing to the east. The shipwrights, who went ashore during the stop, asked St. Peter to come to pray in a house where the owner and all the household were sick. Saint Peter healed them with his prayer.
In a dream, the Most Holy Theotokos appeared to Saint Peter and pointed out the place where he was to live until the end of his days – Holy Mount Athos. When the ship sailed past Mount Athos, it stopped on its own. Saint Peter realized that he had to get off at this place, and went ashore. That was in 681. The Monk Peter spent 53 years in the deserted places of the Holy Mountain, without seeing any of the people. His clothes had rotted away, and his hair and beard had grown out and covered his body instead of clothes.
At first, St. Peter was repeatedly subjected to demonic attacks. Trying to force the saint to leave the cave, the demons took the form of armed warriors, then ferocious beasts and reptiles ready to tear apart the hermit. But by fervent prayer to God and the Mother of God, the Monk Peter defeated demonic attacks. Then the enemy began to act with cunning. Appearing in the guise of a boy sent to him from his native home, he tearfully begged the monk to leave the desert and return to his home. The Reverend shed tears, but answered without hesitation: "The Lord and the Most Holy Theotokos brought me here, I will not leave here without Her permission." Upon hearing the name of the Mother of God, the demon disappeared.
Seven years later, the demon appeared before the monk in the form of a bright Angel and said that God commanded him to go into the world to enlighten and save people who needed his guidance. The experienced ascetic replied again that he would not leave the desert without the command of the Mother of God. The demon disappeared and no longer dared to approach the monk. The Mother of God appeared to St. Peter in a dream together with St. Nicholas and told the courageous hermit that every 40 days an Angel would bring him heavenly manna. Since that time, the Monk Peter fasted for 40 days, and on the fortieth day he was fortified with heavenly manna, receiving strength for further forty days of abstinence.
One day, a hunter chasing a deer saw a naked man, overgrown with hair and girded with foliage at the loins. He got scared and started running. The Monk Peter stopped him and told him about his life. The hunter asked permission to stay with him, but the saint sent him home. The Monk Peter gave the hunter a year for self-examination and forbade him to tell about the meeting with him.
A year later, the hunter returned with his brother, possessed by a demon, and other companions. When they entered the cave of St. Peter, they saw that he had already passed away to God. With bitter tears, the hunter told his companions about the life of St. Peter, and his brother, as soon as he touched the body of the saint, received healing. The Monk Peter died in 734. His holy relics were located on Mount Athos in the monastery of St. Clement. During the iconoclasm, they were hidden, and in 969 they were transferred to the Thracian village of Fotokami.