In 715 the Tang emperor declined the demand of the Türgesh tribe leader Suluk to be recognized as Qaghan, instead offering him the rank of duke in the Tang military. In response, Suluk invaded the Tarim Basin together with the Tibetan Empire, but they were driven out by the cavalry of Ashina Xian. Suluk and his khagan soldiers challenged the Umayyad and Tang control of the oasis towns regularly. But before Suluk's death his soldiers were defeated by the Tang in 736 and by the Umayyad military in 737. At the same time Türgesh tribes established metal industries in Tang controlled Fergana Valley, an area that was also home to important iron production centers. The Karluks, a federation of three Türgesh tribes with settlements in the Tian Shan mountains, were producers and exporters of iron weapons to the Tibetan empire and the Tang dynasty.