The Kopet Dag mountain range forms a jagged northern wall for the region known as Parthia. To the south, the Dasht-e Kavir desert stretches out in an arid expanse. This territory sits in northeastern Iran with parts extending into southern Turkmenistan. Ancient maps show Media on the west and Hyrcania on the northwest. Margiana lies to the northeast while Aria borders the eastern edge. During the Arsacid period, rulers united this area with Hyrcania as a single administrative unit. By the early Sasanian era, the province shifted toward the central Iranian plateau. It then neighbored Pars to the south and Khuzistan to the southwest. The Alborz Mountains marked its northern boundary during these later centuries. In the Islamic era, scholars like Ibn al-Muqaffa described Parthia differently. They claimed it encompassed regions such as Isfahan, Ray, Hamadan, and Azerbaijan. Al-Khawazmi and Hamza al-Isfahani echoed this broader definition of the land.
Achaemenid Subjugation And Administration
Cyrus the Great defeated Median Astyages one year before 520 BC. Parthia became one of the first provinces to acknowledge his rule immediately after that victory. This allegiance secured Cyrus' eastern flanks for his campaign against Sardis. Darius I seized the Achaemenid throne around 522, 521 BC. The Parthians united with Median king Phraortes to revolt against him shortly thereafter. Hystaspes served as governor of the province and suppressed the uprising successfully. The Behistun inscription dates to approximately 520 BC and lists Parthia among governorates near Drangiana. Herodotus recorded that the annual tribute from this satrapy amounted to only 300 talents of silver. Phrataphernes commanded a Parthian unit at the Battle of Gaugamela in 331 BC. He surrendered his governorate to Alexander the Great when the Macedonian arrived there in summer 330 BC. Alexander reappointed Phrataphernes as governor following the defeat of Darius III.