Famous general Xue Rengui, with given name Li (means "polite") and style name Rengui (means Kind and noble), and has been generally known for his style name, was born in Longmen, Jiangzhou County (now Hejin of Shanxi Province) in the 9th year of Daye Period of the Sui Dynasty(613 AD) and died in the 2nd year of Yongchun Period of the Tang Dynasty(683 AD). He made most of his achievements during the reigns of Emperor Taizong and Emperor Gaozong of the Tang Dynasty.

In the late Zhenguan Period in the Tang Dynasty, Emperor Taizong Li Shimin personally led an expeditionary force to conquer Koguryo. It was found that Commandant Liu Jun'ang was surrounded by local army. After hearing the news, Xue Rengui rode alone to the rescue. He fought bravely, killed the enemy general and tied the general's head on his saddle. The enemy troops all surrendered in fear, and Xue Rengui's name became known in the army for rescuing back Jun'ang.

In April of the 19th year of Zhenguan (645 AD), the vanguard of Tang Dynasty reached Koguryo and defeated the enemy army. Emperor Taizong told Xue Rengui: "My generals are all old, and I am trying to find new generals to entrust the frontier military affairs to. I cannot find one better than you. I am less happy about gaining Liaodong than I am about gaining a brave general." Xue Rengui was later reassigned as the Right-Commander in Chief.

For the first few years of Emperor Gaozong's reign, Xue Rengui remained as a commandant who guarded Xuanwumen. In the 5th year of Yonghui (654 AD), when Emperor Gaozong was visiting the vacation palace Wannian Palace (west to modern Linyou County, Shaanxi), there was a mountain torrent on the first night. It rained particularly hard, and a flash flood descended on the North Gate of Wannian Palace. The imperial guards all fled, but Xue did not, and instead climbed up the gate and yelled loudly inside the palace to warn the emperor. Emperor Gaozong quickly got out of his bed and climbed as high as he could, and in a brief time, the water flooded into his bedchambers. The emperor expressed appreciation to Xue for helping him survive the disaster and awarded Xue with a royal horse.

In the third year of Xianqing (658 AD), Emperor Gaozong led an army to conquer Koguryo once again and made Xue Rengui serve as his deputy. Xue defeated the enemy army in Guiduan city (now the valleys of Hun River in Liaoning Province) and killed more than 3,000 enemies.

In the first year of Longshuo (661AD), Emperor Gaozong commissioned the general Zheng Rentai to be the Chief in charge of an operation against 9 factions of Uighur in Tianshan Mountain, while making Xue one of Zheng's deputies. After the army withdrew, a song about Xue's shooting three Uighur generals dead was very popular among the soldiers, "With three arrows the General settled the region of Tiansha; Singing the victory song, the warriors marched into the boundaries of Han". Thereafter, the Uighur declined and made no more trouble on the frontier.

In his later years, Xue was given a variety of roles by Emperor Gaozong, appointed as Guazhou's Military Chief, re-assigned as the Right-Commander in Chief and acting Military Governor of Daizhou to attack Turks in Yunzhou (now Datong of Shanxi) since Turks harried the north border areas of Tang Dynasty. His presence intimidated the Turkic soldiers and he scored a major victory: he slew tens of thousands of enemies, captured over 20,000 enemy soldiers as well as 30,000 horses, sheep and cows.

In the second year of Yongchun Period (683 AD), Xue Rengui died at age 70. After his death, the Court conferred the titles of Grand General of the Left Courageous Guard and Military Governor of Youzhou on him. The authorities also made a hearse to return his body to his hometown.

As a famous general of the Tang Dynasty, Xue Rengui was brave in fighting and adept at maneuvering through battles. He had established brilliant achievements in war and made great contributions to the prosperity of the Tang Dynasty.