 Regardless of the titles , Odaenathus controlled the Roman East with the approval of Gallienus who could do little but to <unk> Odaenathus self achieved status and settle for his formal loyalty . Palmyra itself , although officially still part of the Roman empire , became a de facto allied state to Rome instead of a provincial city . Outside of Palmyra , Odaenathus ' authority extended from the <unk> coast in the north to Palestine in the south . This area included the Roman provinces of Syria , Phoenice , <unk> , Arabia , Anatolia 's eastern regions and later ( following the campaign of 262 ) <unk> and Mesopotamia . 
