The Martyrs Agathonikos, Zoticos, Theoprepios, Acindynos, Severian, Zeno and others accepted death for Christ during the reign of the emperor Maximian (284-305 AD). The Martyr Agathonikos was descended from the illustrious lineage of the Hypasians, and he lived at Nicomedia. Having become well versed in Holy Scripture, he converted many pagans to Christ, including the most eminent member of the Senate (its "princeps" or leader). Comitus Eutolmios was sent to the Pontine (lower Black Sea) region, where he crucified the followers of the Christian Zoticos, who had refused to offer sacrifice to idols. Zoticus himself, he took with him.
In Nicomedia, Eutolmios arrested the Martyr Agathonikos (together with the princeps), and also Theoprepios, Acindynos and Severian. After tortures, Eutolmios ordered that the martyrs be taken to Thrace for trial by the emperor. However, along the way, in the vicinity of Potama, the Martyrs Zoticos, Theoprepios and Acindynos were unable to proceed further behind the chariot of the governor because of wounds received during torture. Therefore, they were put to death. The Martyr Severian was put to death at Chalcedon, and the Martyr Agathonikos together with others was beheaded with the sword by order of the emperor, in Selymbria.
The relics of the Martyr Agathonikos were in a church named for him at Constantinople.