861, who, in 862, started launching raids on Herat before besieging and capturing it on 16 August 867, and again in 872. The Saffarids succeeded in expelling the Taherids from Khorasan in 873.
The S?m?nid dynasty was established in Transoxiana by three brothers, Nuh, Yahy?, and Ahmad. Ahmad S?m?ni opened the way for the Samanid dynasty to the conquest of Khor?s?n, including Her?t, which they were to rule for one century. The centralized Samanid administration served as a model for later dynasties. The Samanid power was destroyed in 999 by the Qarakhanids, who were advancing on Transoxiana from the northeast, and by the Ghaznavids, former Samanid retainers, attacking from the southeast.
Sultan Ma?mud of Ghazni officially took control of Khor?s?n in 998. Herat was one of the six Ghaznavid mints in the region. In 1040, Herat was captured by the Seljuk Empire. Yet, in 1175, it was captured by the Ghurids of Ghor and then came under the Khawarazm Empire in 1214. According to the account of Mustawfi, Herat flourished especially under the Ghurid dynasty in the 12th century. Mustawfi reported that there were "359 colleges in Herat, 12,000 shops all fully occupied, 6,000 bath-houses; besides caravanserais and mills, also a darwish convent and a fire temple". There were about 444,000 houses occupied by a settled population. The men were described as "warlike and carry arms", and they were Sunni Muslims. The great mosque of Her?t was built by Ghiyas ad-Din Ghori in 1201. In this period Her?t became an important center for the production of metal goods, especially in bronze, often decorated with elaborate inlays in precious metals.
Her?t was invaded and destroyed by Genghis Khan's Mongol army in 1221. The city was destroyed a second time and remained in ruins from 1222 to about 1236. In 1244 a local prince Shams al-Din Kart was named ruler of Her?t by the Mongol governor of Khor?s?n and in 1255 he was confirmed in his rule by the founder of the Il-Khan
