Prince of Qi
Sun Chuyue was from Ru Prefecture (汝州, roughly modern Runan, Henan). During the reign of Emperor Taizong, he served on the staff of Emperor Taizong's son Li You () the Prince of Qi. It was said that Li You lacked virtues, and Sun often submitted suggestions to him to change his behavior. After Li You failed in rebelling against his father in 643 and was killed, Emperor Taizong personally examined Li You's archives and found Sun's suggestions; he greatly praised them.