Gao Jiong
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.