Emperor Xuanzong of Tang (xuan3.zong1; 8 September 685 – 3 May 762), personal name Li Longji, was the seventh emperor of the Tang dynasty in China, reigning from 712 to 756 CE. His reign of 44 years was the longest during the Tang dynasty. Through two palace coups, he seized the throne and inherited an empire still in its golden age. He was initially assisted by capable chancellors like Yao Chong, Song Jing and Zhang Yue who were already serving as government officials before Xuanzong ascended the throne. However, under Emperor Xuanzong, the empire reached its turning point and went into sharp decline and near collapse, due to numerous political missteps throughout his long reign, such as over-trusting Li Linfu, Yang Guozhong and An Lushan, with Tang's golden age ending in the An Lushan Rebellion.
List of family of Wu Zetian
Li Longji was born at the Tang dynasty eastern capital Luoyang in 685, during the first reign of his father Emperor Ruizong (Li Dan) – but at that time, Emperor Ruizong's mother Empress Dowager Wu (later known as Wu Zetian), not Emperor Ruizong, was in actual control of power as empress dowager and regent. Li Longji was the third son of Emperor Ruizong, and his mother was Emperor Ruizong's concubine Consort Dou, who was highly ranked. In 687, as the emperor's son, he was created the Prince of Chu. It was said that he was handsome as a child, and was talented in music. He had two older brothers – Li Chengqi, born of Emperor Ruizong's wife Empress Liu, and Li Chengyi (李成義), as well as three younger brothers – Li Longfan (李隆範), Li Longye (李隆業), and Li Longti (李隆悌). He had two full younger sisters, Princess Jinxian (金仙公主) and Princess Yuzhen (玉真公主), who later became Taoist nuns.
In 690, Empress Dowager Wu had her son Emperor Ruizong yield the throne to her, and she took the throne as empress regnant of a new Zhou dynasty, interrupting Tang. She imposed upon Ruizong and his family the surname Wu (武) to match hers. In 692, Li Longji and his brothers were allowed to have residences outside the palace and were given staffs at their mansions.