The citizens of Seleucia , still largely Greek ( the city had been commissioned and settled as a capital of the Seleucid empire , one of Alexander the Great 's successor kingdoms ) , opened its gates to the invaders .
The citizens of Seleucia , still largely Greek ( the city had been commissioned and settled as a capital of the Seleucid empire , one of Alexander the Great 's successor kingdoms , opened its gates to the invaders .