 In the Roman empire 's hierarchical system , a vassal king usage of the King of Kings title did not indicate that he is a peer of the emperor or that the <unk> ties were cut . The title was probably a challenge not to the Roman emperor but to Shapur I ; Odaenathus was declaring that he , not the Persian monarch , was the legitimate King of Kings in the East . A <unk> depicting Hairan I shows him wearing a crown shaped like that of the <unk> monarchs , so it must have been Odaenathus ' crown ; this combination of title and imagery indicate that Odaenathus considered himself the rival of the <unk> and the protector of the region against them . 
