Liu Yuxi, also known as Mengde, was originally from Luoyang, Henan, and was born in Xingyang, Zhengzhou, Henan. He said that his family was in Xingshang, and his hometown was in Luoyang. He also claimed that his ancestor was Liu Sheng, Prince Jing of Zhongshan (some say he was a descendant of the Huns). During the Tang Dynasty, he was a minister, writer, and philosopher, and was known as the "Poetry Hero".
In the ninth year of Zhenyuan, he passed the imperial examination and was awarded the title of Prince Shi. He moved to the Huainan Record Office and joined the army. Du You entered the court as prime minister and moved to supervise the censor. In the last years of Zhenyuan, he joined the "Two Kings and Eight Sima" political group headed by Prince Wang Shuwen. After Emperor Shunzong of the Tang Dynasty came to the throne, he implemented the "Yongzhen Reform". After the failure of the reform, the officialdom rose and fell, and he was repeatedly demoted. In the second year of Huichang, the prince moved in as a guest.
Excellent in both poetry and prose, he covered a wide range of subjects. Together with Liu Zongyuan, he was known as "Liu Liu", together with Wei Yingwu and Bai Juyi, he was known as the "Three Heroes", and together with Bai Juyi, he was known as "Liu Bai". Famous works such as "Inscription", "Bamboo Branch Ci", "Yangliu Branch Ci", and "Woyi Lane". Three philosophical works, "On Heaven", discuss the materiality of heaven and analyze the origin of "Destiny Theory", which has materialistic ideas. He is the author of "Collected Works of Liu Mengde" and "Collected Works of Liu Guests".