Early Life and Apostasy
He was born in the Galatea district of Constantinople and given the name Diamantes. His parents were named Kyriakos and Kyriake. Orphaned at a young age, he grew up undisciplined in his conduct.
By tradition, he was caught committing an unlawful act and, to escape punishment, agreed to convert to Islam — an apostasy from Christ that he later came to regret deeply. This fall, and the repentance that followed it, became the defining turn of his life.
Monastic Life on Mount Athos
Fleeing his former life, Diamantes made his way to Mount Athos and entered the Great Lavra, the monastery of the Holy Trinity founded by Saint Athanasius. There he received the monastic tonsure and the name Damascene.
He spent twelve years in prayer and ascetic discipline and was tonsured into the Great Schema. In time he revealed to his spiritual father his desire to atone for his apostasy through martyrdom.
Confession and Martyrdom
Having resolved on martyrdom, Damascene cut his hair, dressed in the clothing of a sailor, and travelled to Constantinople. There he made the Sign of the Cross at Hagia Sophia, by then converted into a mosque, and publicly proclaimed Christ.
He repeated his confession of faith at the mosque of Sultan Mehmed, denouncing those who heard him as ignorant and deceived, and proclaimed Christ once more in the courtyard of the Grand Vizier. He was arrested and brought before Kara Mustapha, the Grand Vizier, who sentenced him to death.
He was beheaded on November 13, 1681, before the gates of the Ecumenical Patriarchate in the Phanar district of Constantinople.
Relics & Shrines
His relics were later transferred to the island of Chalki and enshrined in the Church of the Holy Trinity.