[3] – 21 July 710), personal name Li Guo'er (李裹兒), was a Chinese princess of the Tang dynasty.
[4] After Emperor Zhongzong died in 710 — a death that traditional historians assert was due to poison, and carried out by Empress Wei and Li Guo'er.
The same biography also recorded that as she was born in times of trouble, Guo'er was pampered by her parents; Empress Wei, in particular, favoured her when she became older, as she was beautiful and eloquent.
In 705, a coup led by Zhang Jianzhi, Cui Xuanwei, Jing Hui, Huan Yanfan, and Yuan Shuji overthrew Wu Zetian and restored Emperor Zhongzong to the throne.
However, Wu Sansi, who was carrying on an affair with Empress Wei, became a trusted advisor of Emperor Zhongzong, and Zhang and his cohorts soon lost power (and eventually all were killed or died in exile in 706).
It was said that among the seven, Li Guo'er had a particularly large staff, and she also sold governmental offices, even to people who were of low social stations, as long as they had the money.
Because the offices she sold had their commissions placed in envelopes that were sealed in a slanted manner to indicate that they need not be approved by the examination bureau (門下省, Menxia Sheng), they were known as the "slanted-sealed officials" (斜封官, xiefeng guan).
She even murdered officials who opposed her, wrongfully occupied lands belonging to others, captured free people, especially children, as slaves, and engaged in other illegal activities.
It seems that the taste of unlimited freedom, vast powers and the splendor of wealth increased her greed and arrogance, all because of her father's love and compassion.
Li Guo'er wanted Wu Chongxun to be buried with honors due an emperor, and Emperor Zhongzong initially was inclined to agree, but after the official Lu Can (盧粲) advised against it, changed his mind—and Li Guo'er, in anger, had Lu demoted to be the prefect of Chen Prefecture (陳州, roughly modern Zhoukou, Henan).
Li Guo'er actions worsened the conflict between her and her aunt, Princess Taiping, and became apparent in the eyes of Emperor Zhongzong.
Traditional historians assert that it was a poisoning (with the poison placed into a cake), carried out after a conspiracy by Empress Wei, her new lovers Ma Qinke (馬秦客) and Yang Jun (楊均), and Li Guo'er—with Li Guo'er's motive being that she hoped that Empress Wei would become "emperor" like her grandmother Wu Zetian and that she could become crown princess.
According to Zizhi Tongjian, during the attack, Li Guo'er was looking at herself in the mirror and putting on makeup when a soldier charged in and killed her.