The origin of Judo lies in Japan where martial arts have been used by the samurai on the battlefield for many centuries. Those techniques were meant to fight an armored opponent in close combat which is why joint locks, pins, and throws proved to be way more efficient than striking. Due to political changes in the 19th century Japan opened up to the western world which brought a constitution and a parliament to the country but also caused major cultural innovations. In this context, a modern military took the place of traditional samurai fighters, and therefore martial arts fell into decline.
In this era, Kano Jigoro, who is nowadays known as the founder of Judo, decided to study Jujutsu at the age of 17. At first, he struggled to find a teacher since many martial arts schools had closed due to the westernization. But eventually, Kano got the opportunity to study several styles of traditional Jujutsu. Only four years later, at the age of 21, Jigoro Kano founded his own dōjō in Tokyo, where he started to pass on his knowledge to a few students. He combined techniques from different Jujutsu styles and followed the principles of ‘maximum efficiency, minimum effort’ and ‘mutual welfare’. He believed that dedicating yourself to those ideals while studying jujutsu can contribute to self-improvement. Since this aspect of working on the individual personality was a central aspect of his martial art Kano decided to change its name from ‘jujutsu’ to ‘judo’. The addition of the -do suffix, literally meaning path, emphasizes that there is more to judo than just the physical aspect.
Later in his life, Kano undertook journeys to Europe and became a member of the International Olympic Committee in 1909 to give more people access to Judo. However, he was concerned that Judo might “develop [to] ‘Contest Judo’, a retrograde form as ju-jitsu was before the Kodokan was founded”. In 1960 Judo was finally included as an official event in the Olympic Games which made it known around the globe. Today Judo is practiced in 184 countries and became a very competitive sport with an emphasis on randori which may have caused some of the original ideals to fall into oblivion.
sources
https://en.wikipedia.org/wiki/Judo#History
https://web-japan.org/kidsweb/virtual/judo/judo01.html
