Taekwondo among many other martial arts has an interesting history. It stretches more than 1000 years back, and in its early forms, it was probably used as a defense against other humans or wild animals.
There is a certain doubt about from where Taewkondo originates, some say China or other Asisatics countries. The history facts does not support anything else than Korea though.
In Korea, the first signs of Taekwondo are dated back to The Three Kingdoms (220-280 A.D.), from a wall painting in a cave build in the kingdom of Koguryo. The painting is of two men fighting. This is just one of many paintings discovered, I several caves.
During WW2, Tae Kyon was prohibited and the only way of training was done so secretly, the Japanese brought with them new arts, such as karate and kung fu. New and old arts melted together, and Tang Soo Do and Kong Soo Do where formed.
After the second world war, a group of instructors was interested in getting the old Soo Bak Doo/Tae Kyon back. Which resulted in 6 of the largest schools joined forces and created Taekwondo. So even though the history goes back all these years, Taekwondo as we know it today. Only dates back to approximately 1945.