Emperor Xuanzong, also known as Li Longji, was the seventh emperor of the Tang Dynasty in China, reigning from 712 to 756 AD. He is often celebrated for his cultural achievements and the flourishing of the arts during his rule, which is considered a high point in Chinese history. His reign is marked by the promotion of poetry, music, and painting, leading to a vibrant cultural scene. Despite his successes, Emperor Xuanzong's later years were marred by political strife and the devastating An Lushan Rebellion, which began in 755 AD. This rebellion significantly weakened the Tang Dynasty and led to a decline in its power. Xuanzong's inability to manage the crisis ultimately resulted in his abdication in favor of his son.