高熲
In spring 599, Yang Su was one of the major generals commissioned to attack Tujue's Dulan Khan, Ashina Yongyulü, along with Gao Jiong and Yan Rong (燕榮). He encountered Ashina Yongyulü's subordinate khan, the Datou Khan Ashina Dianjue. Contrary to prior strategies to first protect his army before engaging, he quickly engaged Ashina Dianjue and defeated him, forcing Ashina Dianjue to flee.