Afghanistan fell to the Achaemenid Empire after it was conquered by Darius I of Persia. The area was divided into several provinces called satrapies, which were each ruled by a governor, or satrap. These ancient satrapies included: Aria: The region of Aria was separated by mountain ranges from the Paropamisadae in the east, Parthia in the west and Margiana and Hyrcania in the north, while a desert separated it from Carmania and Drangiana in the south. It is described in a very detailed manner by Ptolemy and Strabo and corresponds, according to that, almost to the Herat Province of today's Afghanistan; Arachosia, corresponds to the modern-day Kandahar, Lashkar Gah, and Quetta. Arachosia bordered Drangiana to the west, Paropamisadae (i.e. Gandahara) to the north and to the east, and Gedrosia to the south. The inhabitants of Arachosia were Iranian peoples, referred to as Arachosians or Arachoti. It is assumed that they were called Paktyans by ethnicity, and that name may have been in reference to the ethnic Paṣtun (Pashtun) tribes; Bactriana was the area north of the Hindu Kush, west of the Pamirs and south of the Tian Shan, with the Amu Darya flowing west through the center (Balkh); Sattagydia was the easternmost regions of the Achaemenid Empire, part of its Seventh tax district according to Herodotus, along with Gandārae, Dadicae and Aparytae. It is believed to have been situated east of the Sulaiman Mountains up to the Indus River in the basin around Bannu.[ (Ghazni); and Gandhara which corresponds to modern day Kabul, Jalalabad, and Peshawar.