Reliquaries depicting the martyrdom of St. Thomas Becket, such as this one, found in the collection of the British Museum, were very popular throughout Europe. This one shows Becket being attacked by two knights, though contemporary accounts are clear that there were four knights involved. Strange, but also very common; most reliquaries of this sort show only two or three attackers. Granted, space is limited on the front panel, but couldn't they have put the others on the side panel?
Unknown French (Limoges) artist
Reliquary Chasse with Scenes of the Martyrdom of Thomas Becket, ca. 1210
Enamel (champlevé) on copper alloy (gilded)
The British Museum, London