In the first year of Qianfeng (666), Goguryeo's powerful minister Yuan Gai Suwen died of illness, and his son Quan Nan succeeded to take charge of state affairs. Izumi boy's brothers, Izumi Nanjian and Izumi boy, took the opportunity to make trouble and expelled Izumi boy. The spring boy defected to the Tang Dynasty and begged the Tang Dynasty to send troops to help.

In June, Li Zhi sent the right Xiaowei general Qibi He Li as the pacification ambassador of Liaodong Province, the right Jin Wuwei general Pang Tongshan and the Yingzhou governor Gao Kan as the marching chief, and Quan Xiancheng, the son of the Quanyang boy, as the township guide, and marched to Goguryeo together. In December of the same year, Li Zhi appointed Li Tao as the chief of the Liaodong Provincial Army and the pacification ambassador, and served as the supreme commander of the Liaodong front. Xue Rengui also participated in the campaign to conquer Goguryeo.

In September of the second year of Qianfeng (667), Li Tao first attacked Xincheng, which was "the key point in the west of Goryeo", and took advantage of the situation to attack with his army, capturing 16 cities in a row. Quan Nanjian sent troops to attack Pang Tongshan and Gao Kan, who were still in Xincheng, and after Xue Rengui heard the news, he led the army to rescue in time, defeated the Goguryeo army, and beheaded hundreds of ranks. Gao Kan marched to Jinshan, the battle was unfavorable, Goguryeo took advantage of the victory to attack, Xue Rengui led troops to meet the attack, cut the Goguryeo army into two sections, broke the Goguryeo army, beheaded more than 50,000 levels, and took advantage of the victory to capture the three cities of Nansu, Mudi and Cangyan, and joined the Quannan boys.

In this regard, Li Zhi personally wrote to Xue Rengui and said: "In the battle of Jinshan, there were a lot of thieves, you rushed in front of the soldiers, fought hard to kill the enemy, regardless of your own life, rushed left and right, and went forward, and the troops were very courageous, so that this battle was quickly victorious. You should do a good job and fulfill this good name! ”

In February of the first year of the general chapter (668), Xue Rengui led 3,000 people (2,000 people in the Old Tang Book: The Biography of Xue Rengui) to attack the Goguryeo town of Buyeo. At this time, the generals were all small and persuaded him not to advance lightly. Xue Rengui said: "The soldiers are used, not in the crowd. So he led his army into battle.

In this battle, he took the lead, killed and captured more than 10,000 Goguryeo troops, and captured Buyeo City. The Tang army was greatly boosted for a while, and more than 40 cities in Fuyuchuan surrendered one after another.

After that, Xue Rengui triumphantly sang all the way and joined forces with Li Tao's army outside Pyongyang, the capital of Goguryeo, forming a siege of Pyongyang. In September, the monk Xincheng opened the door to accept the Tang army, and Li Tao took advantage of the situation to attack, captured Pyongyang in one fell swoop, and captured Quan Nanjian. At this point, Goguryeo perished.

In this battle, the Tang Dynasty obtained a total of five departments, 176 cities, and 697,000 households, divided them into nine prefectures, 42 prefectures, and 100 counties, and set up the Andong Protectorate to govern the entire old Goguryeo land.

Xue Rengui was awarded the title of General of Right Weiwei and the Protector of Andong Metropolitan of the Inspection School, and was named the Duke of Pingyang County, and led 20,000 troops to stay in Pyongyang ("Old Tang Book: The Biography of Xue Rengui" was written to stay together with Liu Renliang. However, according to the "Old Tang Book: The Biography of Liu Renliang", Liu Renliang asked for Zhishi after the Tang Army returned to the division, and there is no record of staying in the Andong Metropolitan Protectorate.

Xue Rengui moved to Xincheng to raise orphans, support the elderly, control thieves, promote and appoint Goguryeo talents, and commend and reward the people with noble character and excellent behavior. For a time, the Goguryeo people were very happy, and even forgot the pain of losing their country.

In the first year of Xianheng (670), in order to fight against Tubo and recover Tuyuhun, the Tang Dynasty dispatched 50,000 troops to escort the king of Tuyuhun back to Qinghai, with Xue Rengui as the general manager of the Luosa Road march, and Ashina Daozhen and Guo Zhifeng as the deputy governors.

Guo Beifeng is the son of the famous general Guo Xiaoke, who once guarded Shancheng City, he was unwilling to submit to Xue Rengui, and often disobeyed Xue Rengui's moderation.

When the Tang army arrived at Dafeichuan in the south of Qinghai Lake and was about to rush to Wuhai, Xue Rengui said to Guo Zhifeng: "The terrain of Wuhai is dangerous and there is a lot of poisonous gas, and our army will enter the place of death, which is really a dangerous road, but the march will succeed if it is fast, and it will fail if it is slow." The Dafei Ridge here is wide and flat, and two barracks can be set up, and all the military supplies are hidden in the barracks, leaving 10,000 guards behind, and our army can advance quickly, and the enemy can be eliminated if he is not prepared to attack him. ”

Xue Rengui led the army first, and met the Tubo army at the mouth of the river. Xue Rengui defeated Tubo, captured a little, harvested more than 10,000 heads of cattle and sheep, and returned to Wuhai City to wait for backup. Guo Zhifeng was arrogant, did not obey Xue Rengui's orders, and led the grain and grass to move forward slowly.

When Guo Beifeng's army entered Wuhai, more than 200,000 troops from Tubo came to rescue Wuhai and attacked Guo Beifeng's army. Xue Rengui had no choice but to withdraw from the army and stationed in Dafeichuan. Tubo sent more than 400,000 troops to attack the Tang army, but the Tang army was defeated and defeated.

Xue Rengui had no choice but to make peace with the Tubo general about Qinling, so that he could retreat, but Tuyuhun has since fallen. Xue Rengui sighed and said: "This year is the year of Gengwu, Lou Xing is on duty, and he should not go to the west to fight, Deng Ai of Wei died in Shu because of this, and I knew that I would fail." Because of the defeat, Xue Rengui was dismissed from his post and removed from his name as a civilian.

Not long after, the army left behind by Goryeo rebelled, and Xue Rengui was appointed as the governor of Jilindao. During the Shangyuan Dynasty (674-676), he was convicted again and exiled to Xiangzhou, where he returned home after encountering an amnesty from the imperial court.

In the first year of Kaiyao (681), Li Zhi remembered Xue Rengui's old skills, summoned Xue Rengui, and said to him: "In the Wannian Palace before, without you, I would have become a fish. You also once wiped out the nine Turks and Goguryeo for me, and made Mobei and Liaodong bow down to you, this is all your credit, how could I forget. However, I am very sorry that someone told me that you deliberately let the enemy go under Wuhai City and lost the enemy. Now that Liaoxi is unstable, and the roads in Guazhou and Shazhou are impassable, how can you sleep peacefully at home and not give me command to fight? ”

As a result, Xue Rengui was reinstated, and the official worshiped the governor of Gua, the right leading army of the general Wei, and the acting governor of the inspection school.

In the first year of Yongchun (682), Shan Yu inspected the school in Duhufu (ruling the northwest of present-day Inner Mongolia and Lingel), and the tribal official Ashde Yuanzhen defected to Ashina Gu Dulu, who claimed to be the Turkic Khan. Ashide Yuanzhen invaded Bingzhou (now Taiyuan, Shanxi) and Shan Yu to the north of the Duhufu, and invaded Yunzhou, and Xue Rengui was ordered to conquer.

The Turks asked, "Who were the generals of the Tang Dynasty?" He replied, "Xue Rengui." The Turks said, "I heard that General Xue has died in exile in Xiangzhou, how can he be resurrected?" Xue Rengui took off his helmet and went to meet them, and the Turks were shocked when they took a closer look, and they all dismounted and lined up to pay respects, and gradually fled. Xue Rengui took advantage of the situation to pursue, defeated the Turkic army, killed tens of thousands of people, captured more than 20,000 people (one made 30,000), captured more than 30,000 camels, horses, cattle and sheep, and won a great victory in Yunzhou.

In the second year of Yongchun (683), Xue Rengui died at the age of seventy. Gao Zongshu gave him the title of General Zuo Xiaowei and Governor of Youzhou. The government provided carriages and horses to escort the coffin back to its hometown, and another said that it was buried in Jiaxiang County, Shandong Province.

(End of chapter)