Athenogenes was a bishop in Asia Minor who, together with ten of his disciples, was put to death for confessing Christ during the persecution under the emperor Diocletian. The synaxarion places his see at Pidachthoë (also rendered Heracleopolis), a district associated by some accounts with the region south of Neocaesarea, and sets his martyrdom in the city of Sebastea in Cappadocia. He and his disciples are commemorated together on July 16, and his rank in the Church is that of hieromartyr — a bishop who died a martyr's death.
According to the tradition preserved in the lives of the saints, Christianity had spread through the area largely because of Athenogenes' preaching, so that most of the inhabitants of Sebastea were Christians. When the governor Philomachos arranged a great festival in honor of the pagan gods and summoned the citizens to offer sacrifice, the Christians refused. Athenogenes and his ten disciples lived in a small monastery near the city; when soldiers came to seize the bishop they did not find him, and so arrested his disciples instead.
The ten disciples, after enduring severe tortures and continuing to refuse to sacrifice to the idols, were beheaded. The bishop was then taken and tortured, and brought to his own monastery, where he was executed by the sword. The account relates that before his death he heard a voice from heaven repeating to him the promise once given to the penitent thief — "Today you shall be with Me in Paradise" — after which he willingly bent his neck beneath the sword.
By tradition Athenogenes is also associated with the ancient evening hymn "O Gladsome Light" (Phos Hilaron), said to have been a hymn of joy that a martyr Athenogenes left to his disciples. This attribution is traditional rather than securely documented, and some accounts distinguish the bishop of Pidachthoë from a second martyr of the same name credited with the hymn; it is hedged accordingly below.