martyrdom · 306 · Thessalonica
Demetrius is the great protector-saint of Thessalonica, the myroblyte whose shrine was said to exude a fragrant oil, the warrior on the icons beside Saint George, and the figure the city credited with saving it from siege after siege. The historical man is almost invisible: a Christian killed in the Great Persecution, in the tradition a deacon or a proconsul's officer, run through with spears. What is genuinely interesting is where the cult starts. The earliest evidence for a martyr Demetrius is at Sirmium, in Pannonia, four hundred miles up the road, and the Thessalonian cult appears later — the usual explanation being that it travelled with the prefecture when its seat moved, and that Thessalonica then made him wholly its own. This dataset does not have to argue the point, because it is visible in his own record: his person page carries two death places, Thessalonica and Sremska Mitrovica, which is Sirmium. The disagreement is in the data rather than in a footnote.
Whose city is he from?
Thessalonica keeps him, but the oldest evidence puts his cult at Sirmium — and this dataset shows both.