The 20,000 Martyrs of Nicomedia allegedly died in Nicomedia in Bithynia during the rule of Emperors Diocletian and Maximian in the early fourth century. However, the persecution by Maximian and Diocletian lasted only between 303 and 305 (at which point Diocletian retired); this would require at least 200 martyrdoms every week.
A number of those executed, men, women, and children died by capital punishment, while others were burned alive according to accounts.
These saints of the early Church are commemorated 28 December in the Eastern Orthodox Church, and by the Byzantine Catholic and Latin Rite Catholic Churches.[1]