Dating back to 1882, judo is a form of wrestling in which participants are taught to use the opponent's strength against them. It was invented in Japan by Dr. Jigoro Kano, and was derived from jiu jitsu.

Basically, judo is jiu jitsu with all the dangerous techniques removed because participants were getting hurt too often. Judo literally means 'gentle way.' An Olympic sport, it was also taught to secret agents during the second world war.