"Sanskrit Dāsa- as an ethnic name thus has an exact counterpart in Avestan Dåŋha-, which stands for *Dāha-. The corresponding Old Persian ethnic name is Daha-. The plural form Dahā is included among the subjects of the Great King in the “empire list” of Xerxes, immediately before the two kinds of Sakā. Herodotus (1,125) includes the Dā´ai / Dā´oi (intervocalic h is omitted in Greek) among the nomadic tribes of the Persians. According to Q. Curtius Rufus (8,3), the Dahae lived on the lower course of the river Margus (modern Murghab) in Margiana, where they are also located in Ptolemy’s Geography (6,10,2). Eratosthenes, quoted by Pomponius Mela (3,42), notes that the great bend of the Oxus towards the northwest begins near the Dahae. Tacitus (Annales 11,10) places the Dahae on the border river (Sindes, modern Tejend) between Areia and Margiana."