martyrdom · 312 · Nicomedia
He was taken to Nicomedia, Diocletian's capital and the city where the Great Persecution had begun with the burning of the church opposite the palace. Eusebius says he was held a long time and then, before his death, delivered before the emperor an apology for the doctrine he professed — which is as much of a trial record as survives. He died on 7 January, by the received account in 312, near the very end of the persecution and within a year of the toleration edict. What happened afterwards is the odd part: because Arius and Eusebius of Nicomedia had been his pupils, his memory became a possession worth fighting over, and both the Arian party and the church that condemned it kept his feast.
To break a man whose school had produced half the clergy of Bithynia, in the emperor's own city.
A martyr both sides of the Arian quarrel would claim, and a feast in both calendars.