Emperor Xuanzong of Tang ( 8 September 685-3 May 762); also commonly known as Emperor Ming of Tang (Tang Minghuang); personal name Li Longji; known as Wu Longji; was the seventh emperor of the Tang dynasty in China; reigning from 712 to 756. His reign of 43 years was the longest during the Tang Dynasty. In the early half of his reign he was a diligent and astute ruler; ably assisted by capable chancellors like Yao Chong and Song Jing; and was credited with bringing Tang China to a pinnacle of culture and power. Emperor Xuanzong; however; was blamed for over-trusting Li Linfu; Yang Guozhong and An Lushan during his late reign; with Tang's golden age ending in the great Anshi Rebellion of An Lushan.