High Quality Content by WIKIPEDIA articles! Yang Su was a powerful general during Sui Dynasty whose authority eventually became nearly as supreme as the emperor's. Traditional historians generally believed that he was involved in the suspected murder of Emperor Wen in 604, at the behest of Emperor Wen's son Yang Guang (the later Emperor Yang). His son Yang Xuangan later rebelled against Emperor Yang in 613 but was defeated and killed, and Yang Su's other sons were also executed. It is not known when Yang Su was born. His grandfather Yang Xuan was a mid-level official during Northern Wei or its branch successor state Western Wei. Yang Su's father Yang Fu served as a general for Western Wei's successor state Northern Zhou, but in 571, while defending Dingyang, Yang Fu was defeated and captured by the Northern Qi general Duan Shao. Yang Fu refused to surrender and was kept in captivity for the rest of his life, but it is not known when he died.