Inv. 1218 Emperor Trebonianus Gallus, marble from Antakya, 3rd century AD.

The Wikipedia has : "Trebonianus Gallus (Latin: Gaius Vibius Afinius Trebonianus Gallus Augustus; 206 – August 253), also known as Gallus, was Roman Emperor from 251 to 253, in a joint rule with his son Volusianus."

The bust has been cleaned, I prefer the uncleaned one, that was much more of a character.