The Persecution at Nicomedia
Nicomedia, in the region of Bithynia in Asia Minor, was Diocletian's chief residence and home to a large Christian population. After a fire broke out at the imperial court, pagans accused Christians of having set it, and the persecution intensified with great ferocity across the communities of Bithynia. Pagan altars were reportedly set up in the marketplaces, requiring sacrifice before any commerce could be conducted.
The Orthodox tradition records that as many as twenty thousand Christians perished when they were burned inside a church in Nicomedia. Among the many martyrs of this period associated with the city were Dorotheus, Mardonius, Migdonius, Peter, Indes, and Gorgonius, who died by various means; the virgin-martyr Domna, a former pagan priestess, and Euthymius, who died while seeking to bury the bodies of the martyrs; and the soldier Zeno, stoned and beheaded after openly denouncing the emperor.