20,000 Christians martyred by order of Diocletian. They were reported to have all been in the single basilica to celebrate Christmas. While there unquestionably was an endless series of martyrs under Diocletian, it’s likely the ancient sources exaggerated the numbers of this incident. And as the Christmas holy day was not celebrated in the East in 303, they were probably gathered for another feast.
- “Martyrs of Nicomedia“. CatholicSaints.Info. 26 March 2016. Web. 21 February 2017. <>