Choroku no hen was an incident that occurred on December 27, 1457 during the Muromachi period when former retainers of the Akamatsu family attacked angu (emperor's temporary palace) of Gonancho (Second Southern Court), made a surprise assault on the brothers of Sonshuo and Chugio who were descendants of the Southern Court emperor (the latter was a seii taishogun (literally, "great general who subdues the barbarians" of the Southern Court), and took away Shinji (the sacred jewel).
長禄の変（ちょうろくのへん）は、室町時代の長禄元年12月2日(旧暦)（1457年12月27日）に赤松家遺臣らが後南朝の行宮を襲い、南朝の皇胤である尊秀王と忠義王（後南朝の征夷大将軍である）の兄弟を騙し討って、神璽を持ち去った事件。