Four vertically stacked registers of sculpted decoration were carved on each pillar, each separated by elaborate moldings. A label for the Tigris River indicates that there were likely labels on other representations as the builders deemed necessary. Artistic license was taken in the representations, for instance, the Caesar Galerius is shown in personal combat with the Sassanid Shah Narses in one of the panels; although they never met in battle.[citation needed] On the arch a mounted Galerius attacks a similarly mounted Narses with a lance as an eagle bearing a victory wreath in its talons approaches Galerius.