 In real history, Qin Shubao retired after Li Shimin became the emperor because of his illness.It was Li Jing (李靖) and Xu Shiji (徐世勣) rather than Qin Shubao that defeated the Turks.Yuchi Gong (尉迟恭 or Yuchi Jingde 尉迟敬德) was a major character in the latter half of the book Shuo Tang, as well as in the sequel.