Judo was developed in 1882 in Japan by Jigoro Kano as a martial art and physical education sport. It is based on jujitsu but was modified to be less lethal for sport competition. Key principles of judo include maximum efficiency, minimum effort and mutual welfare. It grew internationally and became an Olympic sport in 1964. Judo involves throwing or grappling techniques and can be won by pinning an opponent or making them submit.