 The rulers of Persis, called Fratarakas, also seem to have established some level of independence from the Seleucids during the 3rd century BC, especially from the time of Vahbarz.They would later overtly take the title of Kings of Persis, before becoming vassals to the newly formed Parthian Empire.The Seleucid satrap of Parthia, named Andragoras, first claimed independence, in a parallel to the secession of his Bactrian neighbour.