 In fall 622, Li Shimin was attacking and prevailing over Xu Yuanlang the Prince of Lu, and his army was near Li Fuwei's domain.Li Fuwei, fearing that his loyalty might be doubted, requested to go to Chang'an to pay homage to Emperor Gaozu, taking Kan with him.Before he departed, he left Fu in command, with Wang as Fu's deputy, in actual command of the forces, secretly warning Wang, "If I suffer no ill consequences, make sure that Fu does nothing rash."