When did Li Deyu serve as chancellor to the Tang Dynasty?
Li Deyu
Li Deyu (; 787 – January 26, 850), courtesy name Wenrao (文饒), formally the Duke of Wei (衛公), was an official of the Chinese dynasty Tang Dynasty, serving as a chancellor during the reigns of brothers Emperor Wenzong and Emperor Wuzong and (briefly) their uncle Emperor Xuānzong. He was the leader of the so-called Li Faction in the decades-long Niu-Li Factional Struggles, and was particularly powerful during Emperor Wuzong's reign, dominating the court scene and guiding policies during the campaigns against the crumbling Huigu Khanate and against the warlord Liu Zhen. After Emperor Wuzong's death, Emperor Xuānzong, who had long despised him for his hold on power, had him demoted and banished, where he died in exile.
Li Yu, Prince of De
Li Yu (李裕) (died March 17, 905), né Li You (李祐) (name changed 897), briefly Li Zhen (李縝) (from 900 to 901), formally the Prince of De (德王), was an imperial prince of the Chinese dynasty Tang Dynasty. He was the oldest son of the penultimate emperor Emperor Zhaozong and Empress He and was Crown Prince from 897 to 900. In 900, Emperor Zhaozong was briefly forced by the eunuch Liu Jishu to abdicate in Li Yu's favor; after Emperor Zhaozong was restored, Li Yu was no longer Crown Prince but remained a favored son. After Emperor Zhaozong was assassinated by the powerful warlord Zhu Quanzhong in 904, Li Yu, whom Zhu was apprehensive of, was bypassed in favor of his younger brother Emperor Ai (Li Zuo/Li Zhu), and in 905, Zhu had Li Yu, along with eight of his younger brothers, killed. As Li Yu's brief reign was under duress from a eunuch, he is not typically considered a true emperor of Tang.