According to historical documents, Li Zhi (628 – 683), Emperor Gaozong, was the ninth son of Emperor Taizong Li Shimin and Empress Zhangsun. With the support of his uncle Zhangsun Wuji, he was named Crown Prince at the age of 16. He ascended the throne in the sixth lunar month of the 23rd year of the Zhenguan reign (649 AD).

Contrary to the views of some traditional historians who described him as muddle-headed, weak and mediocre, Li Zhi harbored lofty aspirations in the early years of his reign. He resolved to become a wise and revitalizing ruler to build an enduring foundation for the Tang Dynasty. Assisted by senior ministers including Zhangsun Wuji and Chu Suiliang, he dedicated himself to state affairs, treated virtuous people with courtesy, and faithfully carried forward the policies set by Emperor Taizong. He reclaimed wasteland, implemented the equal-field system, and improved the imperial examination system. During his rule, the population grew rapidly, society was stable, the economy thrived, and people lived in peace and contentment. The Tang Dynasty also expanded its influence into Central Asia. Historians commented on his early governance: "The Yonghui reign brought prosperity and peace to the people, bearing the fine legacy of the Zhenguan era."

In his middle age, Li Zhi suffered from severe dizziness and blurred vision, so he entrusted Empress Wu to handle state affairs. Seizing the opportunity, Empress Wu seized absolute power, and her authority became comparable to that of the emperor. In the first lunar month of 666 AD, Li Zhi and Empress Wu jointly performed the Fengshan ritual on Mount Tai and paid homage to Confucius. From then on, they were respectfully referred to as "Two Sages" across the empire.

Chancellor Shangguan Yi once submitted a memorial criticizing the excessive power of the empress, and was later imprisoned and executed. Li Zhi deeply felt that he had lost control over state power and feared that the Li clan would lose the empire. He planned to abdicate the throne in favor of his eldest son Li Hong, but Li Hong passed away suddenly due to chronic illness. He then appointed his second son Li Xian as the Crown Prince to supervise state affairs, yet Li Xian was soon deposed by Empress Wu on charges of disobedience. Left with no choice, Li Zhi named Li Xian, Prince Ying, the new heir.

In 682 AD, Li Xian had a son named Li Chongrun (posthumously titled Crown Prince Yide). Li Zhi designated Li Chongrun as the Imperial Grandson and made an unprecedented move to establish a separate official mansion for him, hoping to secure the Tang Dynasty’s reign for generations to come.

In the first year of the Hongdao reign, Li Zhi traveled to Luoyang, where he passed away in the Zhenguan Palace the same year. He was 56 years old and had reigned for 34 years. Before his death, he sighed: "If heaven grants me another month or two of life to return to Chang'an, I shall die without regret." He wished to be buried in the Guanzhong area near the imperial capital. In his final edict, he stipulated: "Keep the mausoleum simple and frugal. For unresolved military and state affairs, follow the decisions of the Empress Dowager."

In the fifth lunar month of 684 AD, in accordance with his will, Empress Wu ordered Emperor Ruizong to escort Li Zhi’s funeral procession westward back to Chang'an. In the eighth lunar month, Li Zhi was laid to rest on Liangshan Mountain, and the mausoleum was named Qianling.