 However, later that year, Shi was executed after false accusations by Yang Su, and Yang Yichen was not rewarded for his contributions.Sometime during Emperor Wen's late reign -- the "Renshou" era (601-604), Yang Yichen was promoted to be the commandant at Shuo Province (朔州, roughly modern Shuozhou, Shanxi).In 604, Emperor Wen died—a death that traditional historians, while admitting a lack of direct evidence, generally believe to be a murder ordered by his son, Yang Guang the Crown Prince.