A veteran military commander, Ahnaf ibn Qais, was appointed by Umar for the conquest of Khurasan, which in those time comprises most of present-day north eastern Iran, Afghanistan and Turkmenistan.

Some time after Umar's death Ahnaf was again appointed by Abd Allah ibn Amir for pacifying many revolting areas including Quzestan and Herat.

later after Asad's death a few months later, this success was instrumental in preserving Muslim rule in Central Asia, as the blow to the khagan 's prestige led to his murder soon thereafter and the collapse of Turgesh power.

At the same time, Asad's conciliatory policy towards the native population laid the foundations for its eventual acceptance of Muslim rule and the Islamization of Central Asia.

In 724, immediately after the rise of Hisham ibn Abd al-Malik (r. 724–743) to the throne, Asad's brother Khalid al-Qasri was appointed to the important post of governor of Iraq, with responsibility over the entire Islamic East, which he held until 738.

[6][7] From the early days of the Muslim conquests, Arab armies were divided into regiments drawn from individual tribes or tribal confederations (butun or 'asha‘ir).

Despite the fact that many of these groupings were recent creations, created for reasons of military efficiency rather than any common ancestry, they soon developed a strong and distinct identity.

By the 8th century, this division had become firmly established across the Caliphate and was a source of constant internal instability, as the two groups formed in essence two rival political parties, jockeying for power and separated by a fierce hatred for each other.

In the interim, the sources report variously that the province was run either by the Syrian general Ja'far ibn Hanzala al-Bahrani or by Asad's lieutenant Juday' al-Kirmani.

Julius Wellhausen wrote of him that "His age did not affect the freshness of his mind, as is testified not only by his deeds, but also by the verses in which he gave expression to his feelings till the very end of his life".

This province was part of Iranian world that had been heavily colonised by Arab tribes following the Muslim conquest with the intent of replacing Umayyad dynasty which is proved to be successful under the sign of the Black Standard.

[17] The dynasty, of Persian origin,[18][19][20][21][22][23] was founded by Ya'qub bin Laith as-Saffar, a native of Sistan and a local ayyār, who worked as a coppersmith (ṣaffār) before becoming a warlord.