Query: When was the land under Tibetan empire and Chinese?
Context: It was temporarily under the control of the Tibetan empire and Chinese from 650–680 and then under the control of the Umayyads in 710. The Samanid Empire, 819 to 999, restored Persian control of the region and enlarged the cities of Samarkand and Bukhara (both cities are today part of Uzbekistan) which became the cultural centers of Iran and the region was known as Khorasan.