The Japanese considered it 'forbidden' for Koreans to practice any martial arts from Korea; it was even a punishable offence. As part of their education the Japanese allowed high school students to study judo and kendo, but that was all.

Following the liberation of Korea from Japan in 1945, native Koreans that had fled to other countries during the Japanese occupation began to return to Korea. Some of these returning natives had become masters of martial arts from other countries including Okinawa, Japan, and China. Some of these masters opened the first schools of their respective new martial art in Korea. The five main schools were: Chang Moo Kwan, Song Moo Kwan, Moo Duk Kwan, Ji Do Kwan and Chung Duk Kwon. Minor schools included: Kang Duk Won and Hung Moo Kwan.
These schools were primarily karate and chuan-fa(kung fu) based.

After the Korean War, the Korean government stepped in and decided that Koreans shouldn't be training in non-Korean arts. In order to reaffirm Korean martial arts they enlisted the help of a Korean that had studied karate in Japan. Choi Hong-Hi. Choi had ties with the Korean military and was chosen as Korea's 'posterboy' for the effort. He established the Oh Do Kwan, and created some new forms in March 1950. The names of these forms were derived from events or people in Korean history. This is where the ITF forms practiced today come from. In the 1960's he fled Korea and established the ITF in Canada. He passed away earlier this year. (what year? – mike)

In the late 1950's and early 1960's the Korean government sought to consolidate the original schools in Korea under one name: Taekwondo. This was in the hope that Koreans would forget the old teachings from other countries and only practice what they considered Korean techniques. They also devised a system of scoring for free sparring and competitions.

Most of the original Kwans were assimilated into the new group with a few exceptions. Moo Duk Kwan, Kwan Duk Kwan, and Hung Moo Kwan didn't join. Other Korean Masters left Korea to have the freedom to teach the old ways elsewhere and others simply quit in order to retain their integrity and took jobs so they could afford to take care of their families.

In 1965 the Korean Taekowndo Association was founded. In December 1967 the KTA held clinics that introduced the new black belt Taekowndo forms. Koryo, Tae Baek, Silla, Baek Jae, Sip Jin, Jee Tae. These were first introduced in America by Grandmaster Kim Soo in January 1968. He published an article of the form "Koryo" from New York City in Karate Illustrated. Grandmaster Kim's web site is: www.kimsookarate.com

In 1973 the KTA became the World Taekowndo Federation (WTF), and the first clinics were held in Korea to introduce the below black belt(Gup) forms for rank progression, Palgue.

In 1974, the WTF decided to substitute the Palgue forms with a new series they made up that year: Tae Guek and a new version of Koryo. But, the Palgue forms had already been taught all over the world. This is why some WTF schools teach Palgue and others teach Tae Guek.

Nowadays Taekwondo is mostly taught as a sport for competition, even being ratified as an Olympic sport. Most people that train in Taekwondo are not taught and are not aware of the Taekwondo history and lineage.