The Diocletianic Persecution at Nicomedia
Nicomedia was the eastern imperial capital under Diocletian and a primary locus of the persecution that began in 303. On February 23 of that year, during the festival of Terminalia, Diocletian ordered the destruction of the newly built Christian church at Nicomedia, demanding that its scriptures be burned and its valuables confiscated; the following day he issued the First Edict against Christians, ordering the destruction of churches and scriptures across the empire.
Fires that subsequently broke out in the imperial palace were attributed by Galerius to Christian conspirators, prompting executions of palace staff. Bishop Anthimus of Nicomedia was beheaded on April 24, 303, together with others. The persecution unfolded through four edicts (303–304), the last of which demanded universal public sacrifice on pain of death, and was enforced most severely in the Eastern provinces under Diocletian and Galerius.
Execution methods recorded at Nicomedia and in the East included burning alive, beheading, boiling, and submersion in the sea — the manner of death reported for Gaius, Dasius, and Zoticus. The destruction of a pagan temple, of which they are accused, would have been a capital offense within the edicts' framework of compulsory sacrifice and protection of pagan worship.