The most famous Arsaces was the chief of the Parni, one of the nomadic Scythian or Dahan tribes in the desert east of the Caspian Sea. A later tradition, preserved by Arrian, derives Arsaces I and Tiridates from the Achaemenian king Artaxerxes II, but this has evidently no historical value.
Arsaces, seeking refuge before the Bactrian king Diodotes, invaded Parthia, then a province of the Seleucid Empire, about 250 BC (Strabo xi. p. 515, cf. Arrian p. i, Müller, in Photius, Cod. 58, and Syncellus p. 284).
After two years (according to Arrian) he was killed, and his brother Tiridates, who succeeded him and maintained himself for a short time in Parthia, during the dissolution of the Seleucid empire by the attacks of Ptolemy III (247 ff.), was defeated and expelled by Seleucus II (about 238). But when this king was forced, by the rebellion of his brother, Antiochus Hierax, to return to the west, Tiridates came back and defeated the Macedonians (Strabo xi. pp. 513, 515; Justin xli. 4; Appian, Syr. 65; Isidorus of Charax n).
He was the real founder of the Parthian empire, which was of very limited extent until the final decay of the Seleucid empire, occasioned by the Roman intrigues after the death of Antiochus IV Epiphanes (165 BC), enabled Mithradates and his successors to conquer Media and Babylonia. Tiridates adopted the name of his brother Arsaces, and after him all the other Parthian kings (who by the historians are generally called by their proper names), amounting to the number of about thirty, officially wear only the name Arsaces.
With very few exceptions only the name Αρσακης (with various epithets) occurs on the coins of the Parthian kings, and the obverse generally shows the seated figure of the founder of the dynasty, holding in his hand a strung bow. The Arsacidian empire was overthrown in AD 226 by Ardashir (Artaxerxes), the founder of the Sassanid empire, whose conquests began about AD 212. The name Arsaces of Persia is also borne by some kings of Armenia, who were of Parthian origin.
This entry was originally from the 1911 Encyclopedia Britannica.