[2] The Arab conquest of Pars began in 638/9, when the Rashidun governor of Bahrain at the time, al-'Ala' ibn al-Hadrami, led a naval expedition against the Sasanians without the permission of Umar.

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 to the sea.

[3] Umar, upon hearing of al-'Ala's ill-fated naval expedition against Pars, dismissed him as governor and reassigned him to the Sasanian front in Iraq, where he was placed under the command of his rival Sa'd ibn Abi Waqqas.

[5] The caliphal meanwhile ordered Utbah ibn Ghazwan to send reinforcements to assist Khulayd, who managed to withdraw back to Bahrain with some of his men, while the rest withdrew to Basra.

[2] Al-Thaqafi later managed to establish a military base at Tawwaj, and shortly defeated and killed Shahrag near Rew-shahr, though some sources state that this action was carried out by his brother.

A Persian convert to Islam, Hormoz ibn Hayyan al-'Abdi, was shortly sent by al-Thaqafi to attack a fortress known as Senez on the coast of Pars.