Yang Shidao (died 647), courtesy name Jingyou, posthumously known as Duke Yi of Ande, was a Chinese politician who served as a chancellor during the reign of Emperor Taizong in the Tang dynasty. Background It is not known when Yang Shidao was born. He was a son of Yang Xiong (楊雄), a distant nephew of Sui Dynasty and one of the four most powerful officials at one point early in Sui, with Gao Jiong, Yu Qingze (虞慶則), and Su Wei and who was created an imperial prince with various titles, eventually the title of Prince of Guan. His older brother Yang Gongren served as an official during both Sui and Tang Dynasty and who briefly served as chancellor during the reign of Tang's founder Emperor Gaozu. During Emperor Gaozu's reign At the end of Sui Dynasty, when the state was engulfed in uprisings against Emperor Wen's son Emperor Yang, Yang Shidao was at the eastern capital Luoyang, and was subsequently detained by the general Wang Shichong, who deposed Sui's final emperor Yang Tong (Emperor Yang's grandson) in 619 and established a new state of Zheng as its emperor, but Yang Shidao was eventually able to go to Chang'an, where another general, Li Yuan had established Tang Dynasty as its Emperor Gaozu in 618. (It is not completely clear whether Yang's travel to Chang'an was before or after Zheng's fall to Tang in 621, but likely before.) Late in 621, when Eastern Tujue forces attacked Ling Prefecture (靈州, roughly modern Yinchuan, Ningxia), Yang Shidao was referred to as the commandant at Ling Prefecture, and he was able to repel the Eastern Tujue attack; he would again be involved in a campaign resisting Eastern Tujue attacks in 622. Yang Shidao's older brother Yang Gongren was an old friend of Emperor Gaozu's, and, at some point, Yang Shidao was made a guard commander for Emperor Gaozu's guards. Emperor Gaozu gave Yang Shidao his daughter Princess Guiyang in marriage. Yang Shidao later served as the deputy minister of civil service affairs, and then the minister of rites. He was also created the Duke of Ande—a title that his father had held at one point. In 624, when the crown prince Li Jiancheng's guard commander Yang Wen'gan (楊文幹) rebelled, Yang Shidao was one of the generals whose forces were involved in defeating Yang Wen'gan. During Emperor Taizong's reign In 636, after Emperor Gaozu had succeeded