《旧五代史·后唐·列传十九》
同光三年，魏王李继岌征讨蜀地，请任李愚为都统判官，又带本职随军。
三年，魏王继岌征蜀，请为都统判官，仍带本职从军。
In the third year of Tongguang, Li Jiji, the King of Wei, attacked the Shu region and asked Li Yu to be the governor of the capital, and also took his post to accompany the army.