Jōkyū
13 May 1221 (Jōkyū 3, 20th day of the 4th month): In the 11th year of Juntoku's reign, the emperor abdicated; and the succession (senso) was received by eldest son who was only 4 years old.  Soon after, Emperor Chūkyō is said to have acceded to the throne (sokui).  Chūkyō was emperor for only a few months.