Drangiana in the context of "Sistan Basin"

Sistān (Persian: سیستان), also known as Sakastān (سَكستان, lit. 'the land of the Saka', current name: Zabol) and Sijistan (سِجِستان), is a historical region in south-eastern Iran, and extending across the borders of south-western Afghanistan, and south-western Pakistan. Mostly corresponding to the then Achaemenid region of Drangiana and extending southwards of the Helmand River not far off from the city of Alexandria in Arachosia. Largely desert, the region is bisected by the Helmand River, which empties into the Hamun Lake, located in Zabol, that forms part of the border between Iran and Afghanistan.

Nabarzanes (died c. 330 BC) was a high-ranking Persian commander, who served as the chiliarch of the royal cavalry of the Achaemenid King of Kings Darius III (r. 336–330 BC).

Following the Persian defeat against the Macedonian king Alexander the Great (r. 336–323 BC) at the Battle of Gaugamela in 331 BC, Nabarzanes conspired against Darius III with other Persian grandees, such as Bessus, the satrap of Bactria, and Barsaentes, the satrap of Arachosia-Drangiana. Together they arrested Darius III in mid-330 BC, with Bessus being chosen as the leader of the Achaemenid forces, probably due to his Achaemenid descent. The arrest of Darius III gave Alexander the pretext of avenging him. Fleeing from the pursuing Macedonian forces, Bessus and the rebels carried Darius III in a covered wagon, reportedly in golden chains. In order to buy some time for their escape, Bessus and his co-conspirators killed Darius III and left his body by the road. Bessus then appointed Nabarzanes the satrap of Hyrcania and Parthia, which were under one administrative unit. When Alexander approached Nabarzanes, he surrendered and was pardoned with the help of Bagoas. Nabarzanes then went back to Hyrcania, but was arrested by Phrataphernes, who had him sent to Alexander, where he was seemingly executed.

The Indo-Parthian kingdom, also known as Pahlavas or Pahlawas in ancient Sanskrit texts. was a Parthian kingdom founded by Gondophares in the Indus Valley (modern-day Pakistan) and was active from 19 CE to c. 226 CE. At their zenith, they ruled an area covering parts of eastern Iran, various parts of Afghanistan and the northwest regions of the Indian subcontinent (most of modern Pakistan and parts of northwestern India). The rulers may have been members of the House of Suren, and the kingdom has even been called the "Suren Kingdom" by some authors.

The kingdom was founded in 19/20 when the governor of Drangiana (Sakastan) Gondophares declared independence from the Parthian Empire. He would later make expeditions to the east, conquering territory from the Indo-Scythians and Indo-Greeks, thus transforming his kingdom into an empire. The domains of the Indo-Parthians were greatly reduced following the invasions of the Kushans in the second half of the 1st. century. They managed to retain control of Sakastan, until its conquest by the Sasanian Empire in c. 224/5. In Baluchistan, the Paratarajas, a local Indo-Parthian dynasty, fell into the orbit of the Sasanian Empire circa 262 CE.