Shangguan Wan'er
On 3 July 710, Emperor Zhongzong died suddenly—a death that traditional historians believed to be a poisoning carried out by Empress Wei and Li Guo'er, so that Empress Wei could be Empress Regnant like Wu Zetian and Li Guo'er could be crown princess. Under a will drafted for Emperor Zhongzong by Princess Taiping and Emperor Zhongzong's concubine Consort Shangguan Wan'er, Emperor Zhongzong's son by another concubine, Li Chongmao would be named emperor, with Empress Wei serving as empress dowager and regent, but with Li Dan as co-regent. This plan, however, was opposed by and ultimately altered at the suggestions of Empress Wei's cousin Wei Wen and Zong Chuke. After Li Chongmao took the throne (as Emperor Shang), Empress Wei became empress dowager and regent, while Li Dan only received an entirely ceremonial title of senior advisor to the crown prince (太子太師, "Taizi Taishi") – as there was no crown prince at the time.