Chǔ Suìliáng (596–658), courtesy name Dengshan, formally the Duke of Henan, was a Chinese calligrapher, historian, and politician who served as a chancellor during the reigns of the emperors Taizong and Gaozong in the Tang dynasty. He became increasingly trusted by Emperor Taizong toward the end of his reign and was charged with the responsibilities of serving as the imperial historian and providing honest advice. After Emperor Taizong's death, Chu was entrusted with the responsibilities of assisting Emperor Gaozong, along with Emperor Gaozong's maternal uncle, Zhangsun Wuji and early in the reign of the young emperor, he and Zhangsun Wuji gained great powers. In 655, over his strenuous opposition to Emperor Gaozong's removal of his first wife, Empress Wang, and replacing her with Empress Wu (later known as Wu Zetian), Chu was demoted, and that began a series of demotions, which was successfully launched by Empress Wu. Eventually, he was appointed as the prefect of the Ai Prefecture (愛州, roughly modern Thanh Hóa Province, Vietnam). He died in exile in 658.
Background
Chu Suiliang was born in Hangzhou in 596, during the reign of Emperor Wen in the Sui dynasty. His father, Chu Liang (褚亮), had been a mid-level official during both the Chen and Sui dynasties, and was known for his literary abilities. After Emperor Wen's death in 604, Chu Liang continued to serve Emperor Wen's son, Emperor Yang, but Emperor Yang was jealous of his abilities, and when the general Yang Xuangan rebelled in 613 and was quickly defeated, he accused Chu Liang of being friendly with Yang Xuangan and demoted him to be the census official for the distant Xihai Commandery (西海, in modern Haibei Tibetan Autonomous Prefecture, Qinghai). Chu Suiliang followed his father there.
In 617, when the agrarian rebel leader Xue Ju rose against Sui rule and declared himself the Emperor of Qin, Chu Liang and Chu Suiliang both joined Xue's administration. Chu Liang became a mid-level official, while Chu Suiliang became a low-level official. After Xue Ju's death in 618, his son and successor Xue Rengao was defeated by the Tang dynasty prince Li Shimin (the second son of Tang's founding emperor, Emperor Gaozu). Li Shimin spared Chu Liang and Chu Suiliang, and Chu Liang joined Li Shimin's staff, while Chu Suiliang remained at Qin Prefecture (秦州, roughly modern Tianshui, Gansu) to serve on the staff of the commandant at Qin Prefecture. His activities thereafter, until 636, were not recorded in history, although it was mentioned that he was well-studied in literature and history, and was a talented calligrapher, drawing praise from his father's friend Ouyang Xun, himself a famous calligrapher.
During Emperor Taizong's reign
By 636, when Li Shimin had been emperor for 10 years (as Emperor Taizong), Chu Suiliang was serving as a low-level official in the imperial archival bureau, when he was put in charge of recording Emperor Taizong's acts for historical records. In 640, after Emperor Taizong sent the general Hou Junji to conquer Gaochang, both Chu and Wei submitted petitions requesting that, rather than annexing Gaochang, Emperor Taizong should reestablish Gaochang as a vassal kingdom—advice that Emperor Taizong did not accept but would regret later. (This appeared to, however, begin a pattern where Chu would often offer honest advice to Emperor Taizong, which he often, but not always, accepted, but always respected, and Chu's role in this capacity began particularly more important after Wei's death in spring 643, as Wei had been instrumental in advising Emperor Taizong as to what he was doing properly and what he was doing improperly, for most of Emperor Taizong's reign.)