It was the seat of the driyōšān jādag-gōw ud dādwar (advocate), mowbed (chief priest) and andarzbad (councilor) of Pars.

[4] Istakhr (Middle Persian: Staxr) served as an administrative and religious centre under the Sasanian Empire, which it had done since Achaemenid times.

Darabgerd (Middle Persian: Dārāvkirt, meaning "Darab did it") was a town founded during the Parthian era, and was turned into an administrative division by Ardashir I after he took conquered it.

Arrajan (Middle Persian: Argān), also known as Veh-az-Amid-Kavadh, was a late administrative division founded in the early 6th century by Kavadh I (r. 498–531), who attached a small part of Khuzestan to it[6] and settled prisoners of war from Amid and Martyropolis in the place.

Ardashir spent the rest of the following years fighting other local rulers of Pars and its surroundings, such as the Parthian dynast Mihrak, who ruled Abarsas and Jahrom.

[7] In the early 5th century, a bridge was built in Gor by the Sasanian minister (wuzurg framadār) Mihr Narseh, who was a native of Abruwan, a subdistrict in Ardashir-Khwarrah.

[4] The Muslim invasion of Pars first began in 638/9, when the Rashidun governor of Bahrain, al-'Ala' ibn al-Hadrami, who after having defeated some rebellious Arab tribes, seized an island in the Persian Gulf.

However, things proved to be more fortunate with the third group; Khulayd managed to keep them on bay, but was unable to withdraw back to Bahrain due to the Sasanians blocking his way at the sea.

[10] Umar, founding out about al-'Ala's invasion of Pars, had him replaced with Sa'd ibn Abi Waqqas as the governor of Bahrain.

When the reinforcements arrived, Khulayd and some of his men managed successfully to withdraw back to Bahrain, while the rest withdrew to Basra.

[11] Some time later, Uthman ibn Abi al-As managed to establish a military base at Tawwaj, and shortly defeated and killed Shahrag near Rew-shahr (however other sources states that it was his brother who did it).