Judo came into existence as forms of unarmed combat, which were grouped under the general name "Jujitsu" or "the gentle practice." The object of all these martial arts forms was to avoid an enemy's strength through leverage, speed, and technique. Medieval Japanese warriors practiced many different combat skills. Since Jujitsu was strictly a combat technique, contests were rare and were decided only by the death or crippling of one of the contestants. When Japanese society began to change structurally in the 1860's, feudal lords no longer retained their private armies; the martial arts, including Jujitsu, began to die out. In the early 1880's, Professor Jigoro Kano, a teacher from Tokyo and an expert in many types of Jujitsu, decided to save some of these ancient arts. He modified or eliminated the most dangerous of the Jujitsu techniques and created a new discipline, which he called "Judo" or "the gentle way." Judo is "the gentle way" because the end result is maximum efficiency with minimum effort. As a sport, rather than simply a combat form, Judo includes a code of sportsmanship, a sense of mutual respect, and a system of ethical and moral development. Judo is both an art and a science. As an art, Judo enables its practitioners to gain self-respect, self-confidence, and self-expression; as a science, it involves a mastery of such basic natural laws as gravity, friction, momentum, weight transmission, and unity of forces. From its simple beginnings in nineteenth-century Japan, Judo has spread in popularity throughout the world, even to the point of being introduced as an Olympic Sport in 1964. Its rich, medieval heritage combined with Professor Kano's modern, scientific approach has made Judo into the exciting sport it is today.