The areas controlled by Tang China came under the dynasty's cultural influences and the Turkic influence of the ethnically Turkic Tang soldiers stationed in the region. Indo-European prevalence in Central Asia declined as the expeditions accelerated Turkic migration into what is now Xinjiang. By the end of the 657 campaign, the Tang had reached its largest extent. The Turks, Tibetans, Muslim Arabs and the Tang competed for control over Central Asia until the collapse of the Tang in the 10th century.