The sources regarding Arsaces' differ greatly. He is mostly known from Greek and Roman sources, who were hostile to him and his dynasty due to the later Roman–Parthian Wars. In Iranian national history his descent is traced back to several mythical figures, such as being an descendant of either Kay Kawad, Kay Arash, Dara the son of Homay, or Arash, the heroic archer-figure. The affiliation of Arsaces with Arash is due to the resemblance in their names and Arsaces' coins imitating him as a bowman. According to Roman historian Ammianus Marcellinus, Arsaces was a bandit of low birth, who invaded and conquered Parthia, killing its satrap Andragoras, who had recently declared independence from the Hellenistic Seleucid Empire.