The Iranian king Bahram II (276-293) was not the strongest ruler of the Sasanian dynasty. Having lost a war against the Roman emperor Carus, he accepted the loss of Armenia and Mesopotamia; he had some difficulty in suppressing a revolt by his brother Hormizd II; and he lost power to the Zoroastrian high priest Kartir. Still, Bahram II left no less than ten rock reliefs, three of them in Naqš-e Rustam.

One of these shows an equestrian battle. It can be found immediately below Achaemenid tomb I (Darius II Nothus?). Bahram's enemy wears a Roman helmet and may represent the emperor Carus, but he can also be a local ruler who had modelled his army on the imperial units. Next to Bahram, his standard-bearer is visible.

This relief is very lively, completely different from all preceding Sasanian reliefs, except for Firuzabad I. A convincing explanation for this sudden change in artistic style has not yet been found.

Source Livius.org