the same as in the country of Kuci or modern Kucha", some to the east, "but the spoken language is somewhat different" from the Kuchean language, which is also known as Tocharian B and West Tocharian. He also stated that fine cotton and hemp cloth made in the area was traded in neighbouring countries. Contested period In the 7th, 8th, and early 9th centuries, control of the entire region was often contested by Tang China, the Tibetan Empire, and the Uyghur Khaganate; cities frequently changed hands. Tibet seized Aksu in 670, but Tang forces reconquered the region in 692. The Tang general Tang Jiahui led the Chinese to defeat an Arab-Tibetan attack in the Battle of Aksu (717). The attack on Aksu was joined by Türgesh Khan Suluk. Both Uch Turfan and Aksu were attacked by the Turgesh, Arab, and Tibetan force on 15 August 717. Qarluqs serving under Chinese command, under Arsila Xian, a Western Turkic Qaghan serving under the Chinese Assistant Grand Protector General Tang Jiahui defeated the attack. Al-Yashkuri, the Arab commander and his army fled to Tashkent after they were defeated. Tibet regained the Tarim Basin in the late 720s, and the Tang dynasty again annexed the region in the 740s. The Battle of Talas led to the gradual withdrawal of Chinese forces, and the region was then contested between the Uyghurs and Tibetans. Aksu was positioned on a junction of trade routes: the northern Tarim route Silk Road, and the dangerous route north via the Tian Shan's Muzart Pass to the fertile Ili Valley. Mongol era In 1207–08, they submitted to Genghis Khan. Around 1220, Aksu became the capital of the Kingdom of Mangalai. The area had been part of the whole Mongol Empire before it was occupied by the independent-minded Chagatai Khanate under the House of Ögedei in 1286 from the hands of Kublai's Yuan dynasty. After the decline of the Yuan in the mid-14th century and subsequently the Chagatai Khanate in the late 14th century, Aksu fell under the power of Turkic and Mongol warlords. Along with most of Xinjiang, Aksu fell under the control of the Khojas, and later that of Yaqub Beg, during the Dungan Revolt of 1864–1877. Yakub Beg seized Aksu from Chinese Muslim forces. After the defeat of the rebellion, a learned cleric named Musa Sayrami (1836–1917), who had occupied positions of importance in Aksu under both rebel regimes,