Apasiacae is the name of a nomadic tribe belonging to the Massagetae. The Apasiacae lived in between of Oxus and the Tanais River, which in this context meant the east coast of the Aral Sea. That is, "Tanais" here means either the Syr Darya (Jaxartes River), or Amu Darya (Oxus River), to the west of Bactria. The Parthian king Arsaces I fled to these people ca. 230 B.C. from Seleucus II Callinicus.