Prior to the 15th century, Okinawa, a small island located south of Japan, was divided into three kingdoms: Chuzan, Hokuzan, and Nanzan. After much political turmoil, Okinawa was united under the Sho Dynasty in 1429. In 1477, Emperor Sho Shin came into power. Determined to enforce his philosophical and ethical ideas, while banning feudalism, the emperor instituted a ban on weapons. It became a crime to carry or own weapons such as swords, in an attempt to prevent further turmoil and prevent uprising.