Illig Qaghan (Old Turkic: 𐰃𐰞𐰞𐰃𐰏𐰴𐰍𐰣, chinese: 頡利可汗/颉利可汗, Pinyin: xiélì kěhàn, Wade-Giles: hsieh-li k'o-han, Baghatur shad (莫賀咄設/莫贺咄设), personal name: 阿史那咄苾, āshǐnà duōbì, a-shih-na to-pi), later Tang posthumous title Prince Huang of Guiyi (歸義荒王/归义荒王), was the eleventh qaghan of the Eastern Turkic Khaganate. He attacked the Tang empire and was defeated by a revolt of the Tiele tribes led by the Uyghurs and the Syr-Tardush. He was the final Qaghan of the first Eastern Turkic Khaganate; the Western Turkic Khaganate continued for 28 more years.
In 627 he attempted to levy horses from the vassal Tiele tribes after all his livestock died from a summer snowstorm. The Tiele revolted under a Xueyantuo coalition. Emperor Taizong of Tang wasted no time in allying with these Tiele and the Khitans in a joint attack. Bagatur was already facing internal dissent from the Göktürk generals jealous of the influence of Bagatur's Sogdian vizers. Bagatur was defeated and captured in 630. He was bought back to Chang'an to face Taizong. After listing his crimes against the Tang State, Taizong spared the former Qaghan. In his later years, Taizong offered Illig Qaghan military position in the frontier territories, which was turned down by the latter.