Emperor Xuan Zong of Tang, also known as Li Longji, ruled from 712 to 756 AD during the Tang Dynasty in China. He is often remembered for his efforts to promote culture and the arts, leading to a flourishing of poetry and music. His reign is considered a high point in Chinese history, marked by economic prosperity and territorial expansion. However, Xuan Zong's later years were marred by the An Lushan Rebellion, which began in 755 AD. This devastating conflict weakened the Tang Dynasty and led to significant loss of life and territory. Despite his initial successes, the rebellion ultimately overshadowed his legacy.