to bring Balkh under their control only in 715 AD, in spite of strong resistance offered by the Balkh people during the Umayyad period. Qutayba ibn Muslim al-Bahili, an Arab General was Governor of Khurasan and the east from 705 to 715. He established a firm hold over lands beyond the Oxus for the Arabs. He fought and killed Tarkhan Nizak in Tokharistan (Bactria) in 715. In the wake of Arab conquest, the resident monks of the Vihara were either killed or forced to abandon their faith. The Viharas were razed to the ground. Priceless treasures in the form of manuscripts in the libraries of monasteries were consigned to ashes. Presently, only the ancient wall of the town, which once encircled it, stands partially. Nava-Vihara stands in ruins, near Takhta-i-Rustam. In 726, the Umayyad governor Asad ibn Abdallah al-Qasri rebuilt Balkh and installed in it an Arab garrison, while in his second governorship, a decade later, he transferred the provincial capital there. The Umayyad period lasted until 747, when Abu Muslim captured it for the Abbasids (next Sunni Caliphate dynasty) during the Abbasid Revolution. The city remained in Abbasid hands until 821, when it was taken over by the Tahirid dynasty, albeit still in the Abbasids' name. In 870, the Saffarids captured it. From Saffarids to Khwarezmshahs In 870, Ya'qub ibn al-Layth al-Saffar rebelled against Abbasid rule and founded the Saffarid dynasty at Sistan. He captured present Afghanistan and most of present Iran. His successor Amr ibn al-Layth, tried to capture Transoxiana from the Samanids, who were nominally vassals of Abbasids, but he was defeated and captured by Ismail Samani at Battle of Balkh in 900. He was sent to the Abbasid Caliph as a prisoner and was executed in 902. The power of Saffarids was diminished and they became vassals of the Samanids. Thus Balkh now passed to them. Samanid rule in Balkh lasted until 997, when their former subordinates, the Ghaznavids, captured it. In 1006, Balkh was captured by Karakhanids, but Ghaznavids recaptured it 1008. Finally, the Seljuks conquered Balkh in 1059. In 1115, it was occupied and looted by irregular Oghuz Turks. Between 1141 and 1142, Balkh was captured by Atsiz, Shah of Khwarezm, after the Seljuks were defeated by the Kara-Khitan Khanate at the Battle of Qatwan. Ahmad Sanjar decisively defeated a Ghurid army, commanded by Ala al-Din Husayn and he took him prisoner for two