Meanwhile, "a man called Arsaces, of Scythian or Bactrian[a] origin, [was] elected leader of the Parni tribes."[3] Following the secession of Parthia from the Seleucid Empire and the resultant loss of Seleucid military support, Andragoras had difficulty in maintaining his borders, and about 238 BCE—under the command of "Arsaces and his brother Tiridates"[3][4]—the Parni invaded[5] Parthia and seized control of Astabene (Astawa), the northern region of that territory, the administrative capital of which was Kabuchan (Kuchan in the vulgate).