Emperor Ruizong of Tang (Li Dan): life and significance

Names, titles and position

Over his life Li Dan used several names and styles, reflecting changes in status and the political order: Li Dan is his most commonly used personal name, but historical records also note variations such as Li Xulun, Li Lun, and names adopting the Wu surname while his mother exercised supreme authority. He is conventionally counted as the fifth and later the ninth emperor of the Tang dynasty because of the interruptions and restorations common to this era.

Political context and role

Ruizong’s first accession occurred during the period when his mother, Empress Dowager Wu, assumed de facto control of the government. For much of that time he functioned as a ceremonial sovereign while real authority rested with powerful relatives and court factions. His second reign came after the restoration of the Tang house following Wu Zetian’s overthrow and a brief period of upheaval; again, his authority was limited and he ultimately abdicated in favour of his son, who became Emperor Xuanzong.

Notable individuals and factions

• Wu Zetian: Ruizong’s mother, who briefly interrupted Tang rule to establish the Zhou dynasty.
• Emperor Zhongzong: his brother, whose own deposal and restoration shaped succession disputes.
• Princess Taiping and Li Longji (later Emperor Xuanzong): influential family members whose rivalry influenced Ruizong’s final years and the transfer of power.

Legacy and significance

Historians view Ruizong as a ruler whose personal temperament and position left him overshadowed by dominant courtiers and kin. His life illuminates the fragility of imperial authority in a period when regents, palace factions, and military players could determine succession. The events around his reigns helped set the stage for the long and prosperous reign of his son, Emperor Xuanzong, who would preside over one of Tang China’s high points.

Notable facts: Ruizong’s two nonconsecutive reigns exemplify how familial power struggles and the extraordinary role of Wu Zetian shaped the late seventh- and early eighth-century court. For more on his parents and brother, see pages on Gaozong, Wu Zetian, and Zhongzong.