Complex sentence: The Tang dynasty had reconquered the Tarim Basin by the 7th century AD and for the next three centuries the Tibetan Empire, the Tang dynasty, and the Turks fought over dominion of the Tarim Basin.
Split into simpler sentences: The Tang dynasty had reconquered the Tarim Basin by the 7th century AD. During the 7th, 8th, and early 9th centuries the Tibetan Empire, the Tang Chinese, and Turks fought to conquer the Tarim Basin.