In the third century, a Turkish Roman soldier joined a growing cult and was executed for it, inspiring other martyrs. When the cult later became the official religion of the Roman Empire, the soldier inspired a popular cult of his own in Palestine...

The Empire persisted as a religious power structure in Europe and the Middle East, and many churches were dedicated to that Turkish soldier, right across the territory of the old empire - from the Levant in the east to Britain in the west.

The military cult became associated with orders of knighthood across Europe in the Middle Ages. When England split away from the church still run from Rome, all banners of saints except for that of the Turkish soldier were banned - he was just too popular.

At some point, a myth about dragon-slaying became attached to that soldier.
He became adopted as the patron saint of many territories that he never set foot in: Georgia, Ethiopia, Aragon and Catalonia, Portugal, Brazil, Bulgaria, Moscow, Serbia and Montenegro... and England.