《明史·列传·卷三十七》
八年，皇上北征，原吉辅佐太孙留守北京，总管行在所九卿事务。
八年，帝北征，辅太孙留守北京，总行在九卿事。
In the eighth year, the emperor marched north and Yuan Ji assisted the crown prince in defending Beijing, and was in charge of the affairs of the Nine Ministers.