Meanwhile , Du Yan 's nephew Du Ruhui had become an important advisor to Li Shimin , a son of rival Tang Dynasty 's Emperor Gaozu and a major Tang general .
Wang made Du Yan the minister of civil service affairs and trusted him greatly .
Du Yan 's nephew Du Ruhui had become an important advisor to Li Shimin , a son of rival Tang Dynasty 's Emperor Gaozu and a major Tang general .
Wang made Du Yan the minister of civil service affairs and trusted him greatly .