Ishbara Khagan (Old Turkic: 𐰃𐱁𐰉𐰺𐰀𐰴𐰍𐰣, Ϊšbara qaγan, Chinese: 沙缽略可汗/沙钵略可汗; pinyin: shābōlüè kěhàn, personal name Ashina Helu Chinese: 阿史那賀魯/阿史那贺鲁; pinyin: āshǐnà hèlǔ - ) (ruled 651–658) was the last khagan of the Western Turkic Khaganate.
His Turkic name became a debate among scholars. Gömeç argued his name should be read as Ulug meaning "Great", meanwhile Gumilov proposed Hallıg which would mean "Elevated". Von Gabain proposed name Kullıg (slave owner). Kapusuzoğlu proposed Kutlug (Blessed) as alternative name transcription.
His parentage is uncertain. According to Gumilov his father was Böri Shad, however Chavannes attributes him to be a son of Irbis Seguy. He was awarded with the title shad by Dulu khagan in 633 and oppointed to govern certain tribes including Chuye, Qarluq, Nushibi. In 646 he rose against Irbis Seguy only to be defeated by him. He fled to China in 25 April 648 and had served the Tang dynasty as a general stationed in Mohe (莫賀) city in Gansu.
However he soon started to plan to assert independence using Taizong's death in 649. Qiao Baoming (橋寶明) personal staff of Gaozong tried to avert it by ordering him to deliver his son Ashina Xiyun (阿史那咥運) to serve in palace guard. Xiyun served for a while before returning to Helu again and encouraging him to attack Irbis Dulu khagan.
After a while he set up his horde near modern Shuanghe, began to receive submissions. According to Tongjian firstly Dulu tribe chiefs who were titled as čor, namely Chumukun chief Lü (處木昆律啜), Huluwu chief Jue (胡祿居闕啜), Turgesh chief Heluoshi (突騎施賀邏施啜), Shunishi chief Chupan (鼠尼施處半啜) submitted. Huluwu chief was also a son-in-law to Helu. Nushibi tribal chiefs who were titled irkin also submitted - Axijie chief Kül (阿悉結闕俟斤), Geshu chief Kül (哥舒闕俟斤), Basaigan chief Tong Ishbara (拔塞幹暾沙鉢俟斤), Axijie chief Nishu (阿悉結泥孰俟斤) another Geshu chief Chupan (哥舒處半俟斤).  Ashina Xiyun was appointed crown prince with the title Bagatur Yabgu.
After formally reasserting independence from Tang, he commanded raids to Jin Ling (金嶺城, near modern Shanshan, Xinjiang) and Pulei (蒲類縣). Angered Gaozong stripped him of Chinese titles and ordered Qibi Heli and Liang Jianfang (梁建方) to secure border areas.
Conflicts also began in southern border when Zhenzhu yabgu (son of Yukuk Shad) started major incursions to Western Tujue territory. Later Zhenzhu contacted Tang to receive soldiers and requested to be created a qaghan in 655. Yuan Lichen (元礼臣) was ordered by Gaozong to visit Zhenzhu in 8 November 656 to create him khagan, but he was stopped by Helu's soldiers near Suyab, causing Zhenzhu to lose much prestige.
In 657 Emperor Gaozong of Tang started the Conquest of the Western Turks. General Su Dingfang was appointed to be leading commander during whole operation. Chumukun tribe was first to lose whose chief Lantulu (懶獨祿) submitted. Tang army defeated Ishbara at the Battle of Irtysh River. However he fled to Chach with his son Ashina Xiyun and a noble retainer Xuyan. However he was soon handed over to Xiao Siya (萧嗣业) by Chach ruler Yixian Tarkhan.
- Gabain, Eski Türkçenin Grameri, TDK Yayınları, s. 284: kullıg: köle sahibi.
- Kapusuzoğlu, Gökçen (Spring 2016). "An Analysis on Western Turkic Qaghan Ashina He-lu (Kutlug)'s Turkish Name and His Biography". Gazi Üniversitesi Türkiyat Araştırmaları Dergisi – via ResearchGate.
- Ouyang Xiu, "Xin Tang shu (History of Tang dynasty", 618-907, New Edition)], Peking, Bo-na, 1958, Ch. 215b, p. 1506, f. 56
- Xiang, Han (2006), Dust in the Wind: Retracing Dharma Master Xuanzang's Western Pilgrimage, Rhythms Monthly, p. 137
- Zhizhi Tongjian 6310, 6311: "…阿史那賀魯既被擒，謂蕭嗣業曰：「我本亡虜，為先帝所存，先帝遇我厚而我負之，今日之敗，天所怒也。吾聞中國刑人必於市，願刑我於昭陵之前以謝先帝。」上聞而憐之。賀魯至京師， 甲午，獻於昭陵。敕免其死，分其種落為六都督府，其所役屬諸國皆置州府，西盡波斯，並隸安西都護府。賀魯 尋死，葬於頡利墓側。"
- Christoph Baumer, History of Central Asia, volume two, 2014, index