Historical Context
Valerian's traditional date of martyrdom, 274, falls within the reign of the Emperor Aurelian, a period associated in the calendar tradition with persecution of Christians. He is grouped in the same November 29 commemoration as Philoumenos of Ancyra, who by tradition suffered under Aurelian at Ancyra (modern Ankara, Turkey) after refusing to sacrifice to idols, and as Phaedrus.
The shared feast day and year have led sources to suggest that Valerian belonged to the same wave of persecution, possibly in or near Ancyra, though no source records the place of his own martyrdom directly. The calendar preserves only that he died by the sword.