Life
Qapaghan Qaghan meaning "Conqueror" was the second khagan of the Second Turkic Khaganate and was the younger brother of the first kaghan, Ilterish Qaghan. Reigned between 692 - 716. He was born in 664.
Göktürk Independence War
In 681, he assisted his brother, Ilterish Qaghan, in a revolt against Tang dominion, and succeeded in reviving the Turkic Khaganate in Göktürk independence war. He fought against Tang in command of his elder brother Ilterish Qaghan and friend Tonyukuk. And with his younger brother Duoxifu. Tonyukuk served as grand vizier of Turkic Khaganate during Ilterish Qaghan and also Qapaghan Qaghan. In 689, he led a raid to frontier areas of Tang Dynasty. In reaction, Empress Wu sent Huaiyi to fortify. He advanced to Zi River but did not encounter Tang forces. He erected a monument at Chanyu Tower (in modern Hohhot, Inner Mongolia) before withdrawing. In 692, he succeeded his brother as khagan. In 694, Qapaghan attacked Ling Prefecture. Empress Wu Zetian commissioned Huaiyi, assisted by the chancellors Li Zhaode and Su Weidao, to defend against Qapaghan's attack. but before the army could set out, Qapaghan plundered too much lands and withdrew, and therefore Huaiyi's army never launched.
Göktürk-Khitan War of 697
In summer 696, The Khitan chieftains Li Jinzhong and Sun Wanrong brothers, angry over the mistreatment of the Khitan people by the Zhao Wenhui rebelled. Armies that Empress Wu Zetian sent to suppress Li and Sun's rebellion were defeated by Khitan forces. Tang forces cannot do anything against Khitan. During the winter of 696, shortly after Li's death, Sun, after taking over as emperor and reorganizing Khitan forces, again attacked Tang territory and had many victories over Tang forces, including a battle during which Wang Shijie was killed. Empress Wu Zetian decided to ask help from Göktürks against Khitan. Göktürks were enemies of Tang but also enemies of Khitans. Wu Zetian tried to fix the situation by making peace with khagan at fairly costly terms and providing Turks with seeds, silk, tools, and iron. Empress encouraged Qapaghan to eventually attack Khitans and plunder on their rear, to his full benefit. She did very expensive deals with Göktürks to save her country against Khitan attacks. In summer 697, Qapaghan launched attack on Khitan's base of operations, and this time, after his attack, Khitan forces collapsed and Sun was killed in fight against Qapaghan. Qapaghan ended the Khitan threat against Tang. Empress Wu gave him the title Qianshan Khagan, literally meaning "Good moving khagan".
Göktürk-Tang War of 698-711
In 698, Qapaghan demanded a Tang dynasty prince for marriage to his daughter, part of a plot to join his family with the Tang, displace the Tang, and restore Tang rule over China under his influence. When Wu Zetian sent a member of her own family, grandnephew Wu Yanxiu, to marry Qapaghan's daughter instead. Zhang Jianzhi opposed, stating, "In ancient times, no Chinese imperial prince had ever married a barbarian woman as his wife." This opposition drew displeasure from Wu Zetian, as she wanted peace with Turks, and she demoted Zhang to be the prefect of He Prefecture. Khagan nevertheless rejected the prince. He had no intention to cement the peace treaty with a marriage; instead, launched a major attack on Tang. First Tang general Murong Xuanjiao also submitted to Qapaghan with 5000 soldiers. In August 698, Qapaghan attacked Dingzhou, captured and killed its governor Sun Yangao then burned the city. Empress Wu Zetian angered too much and she issued a proclamation that if anyone killed the khagan would be a new prince of Tang Dynasty. In September, Zhaozhou was also attacked, deputy governor Tang Boruo handed over the keys to Qapaghan and governor Gao Rui was immediately executed. In 699, he appointed his younger brother Duoxifu as Yabgu, governor eastern wing, his nephew Bilge as governor of western wing with each of them commanding 20000 men, also putting his son Inel as their overseer, creating him as lesser khagan.
However, the new emperor of Tang, Zhongzhong's accession changed political climate. In 705, Göktürk forces entered Lingwu, defeating Shazha Chongyi. Angered Emperor Zhongzhong proclaimed prize for anyone willing to kill Qapaghan.
Emperor Zhongzhong decided to gather an big army to destroy Göktürks and Qapaghan. He gather an army of 80.000 men. Those big Tang forces given under command of General Shazha Zhongyi faced against small numbers of Göktürk army in Ming Sha. Qapaghan Qaghan, Kul-Tigin and Bilge commanded Göktürk forces in this Battle of Ming Sha. Göktürks win a decisive victory in this battle and destroyed almost half of Tang army.
In 711, khagan sent a marriage proposal to Ruizong, this time intending to marry a Tang Princess. Emperor Ruizong accepted and give Princess Jinshan to Qapaghan. Khagan give princess to his son Inel. After that year, some Turkic tribes rebelled against him and Qapaghan and Tonyukuk defeated most of them.
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, Qapaghan Qaghan was still fighting against Tang Dynasty, while also dealing with the rebellious Turkic tribes. He did not go and fight himself. He sent his 2 sons, Inel and Tona. During the Siege of Beiting in these wars, Qapaghan's son Tona died. 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.
Death
Qapaghan was on his way back from suppressing the revolting Tiele tribes of Huihe, Tongluo, Baixi, Bayegu and Pugu, was ambushed killed by a tribesman named Xiezhilue on July 22, 716 while passing through a forest. His son Inel came back from the war against Umayyad and succeded his father as khagan.