Life
Inel Qaghan was the third khagan of Second Turkic Khaganate. He actively participated in his father's campaigns. He helped every time his father with his wars. He became lesser khagan and received from his father 20,000 troops of the western wing, so the Chinese called him Tuoxi Kehan literally means (the expander of the west) in 699.
Göktürk-Umayyad War
Recapture of Samarkand by the Turkic Khaganate was perceived as a threat to the Umayyads. In those years, the Umayyads were already at war against the Khazar Khaganate, who was a former Göktürk vassal. Because of this, the Umayyads declared war on the Turkic Khaganate with the army under the command of Qutayba. Small-scale conflicts continued until 711. Meanwhile, his father Qapaghan Qaghan was still fighting against Tang Dynasty, while also dealing with the rebellious Turkic tribes. Thats why his father Qapaghan Qaghan did not go and fight himself. He sent his 2 sons, Inel and Tona. He took part in battles involving Umayyad attacks. One of those battles his brother Tona died. This battle was Siege of Beiting, where his brother Tona Tegin was killed in 714. Inel, on the other hand, continued the struggle. In these wars, which lasted until 716, neither side could reach a conclusion. We cannot say that the Göktürk-Umayyad wars were great wars. The main wars were the Turgish-Umayyad and Khazar-Umayyad wars. The Umayyads attacked the Göktürks quite unnecessarily, and from our point of view, this war did not go beyond harming both sides unnecessarily. He went back from this war after he heard about death of his father Qapaghan and became new khagan of Turkic Khaganate.
Death
However, his cousin Kul-Tigin was not happy with his reign. Kul-Tigin did a coup against Inel. Inel was killed by Kul-Tigin during struggle for the throne. Some writers say that the law of succession of Göktürks was that power passed from a ruler to his younger brothers before returning to his sons. Thats probably why Kul-Tigin didn't accepted Inel as khagan. His uncle Duoxifu defended him in this coup but he also was killed by Kul-Tigin. Thus the throne was first the right of Ilterish, eldest brother. Then Qapaghan, younger brother. Then, sons of Ilterish, eldest Bilge and then younger Kul-Tigin. Then Inel should be khagan after Bilge and Kul-Tigin. Inel, being Qapaghan's son, had no right on the throne. Inel and his supporters was killed by Kul-Tigin in 717. And Bilge became the khagan.