Saint Theogenes — his name also given as Theagenes — was bishop of Parium, a port city on the Hellespont (the modern Dardanelles) in northwestern Asia Minor, in the late third and early fourth centuries. The surviving accounts say little of his early life or education; they begin with him already serving as bishop, overseeing the local community, ministering the sacraments, and guiding his flock through a time of political uncertainty.
His martyrdom is placed in the reign of Licinius (308–324), who governed the East as co-emperor with Constantine. Though Constantine increasingly favored the Christians, Licinius eventually turned to policies hostile to the Church within his own territories.
According to Orthodox tradition, an official — named in the sources as Zelicinthius — ordered Theogenes to abandon the priesthood, renounce Christ, and enter military service. When the bishop refused, he was beaten and imprisoned, and the accounts say he was deprived of food during his confinement.
When repeated pressure failed to move him, he was condemned to die by drowning. Tradition records that he asked for time to pray before the sentence was carried out, that a brilliant light surrounded him as he did so, and that some of the soldiers and sailors who witnessed it were moved to embrace Christ. He was then cast into the sea; later accounts hold that his body was recovered and buried by the faithful, and that a shrine grew up at his tomb.
The exact year of his death is uncertain, falling somewhere within the persecution under Licinius, between about 311 and 324. Because he suffered as a bishop, the Church venerates him as a hieromartyr.