Victory relief of Shapur at Naqs-i Rustam, Persia, c.260 AD
A larger image of the Victory relief of Shapur at Naqs-i Rustam, Persia, c.260 AD
Figure 32 in The Enemies of Rome from Hannibal to Attila the Hun by Philip Matyszak
32 Victory relief of Shapur at Naqs-i Rustam. The cloaked figure kneeling before the king is the captured emperor Valerian, and from this pose it is easy to understand the tradition that Shapur was in the habit of using him as a human mounting-block to get onto his horse.
See also a Sasanian Cameo of Shapur I vanquishing Emperor Valerian, 260 AD
Ancient Illustrations of Costume & Soldiers
Persian Illustrations of Costume & Soldiers