Tangsoodo or Tang Soo Do (唐手道 / 당수도, Sino-Korean: The Way of the Tang Hand) is a traditional Korean martial art that has been largely incorporated into modern Taekwondo.

Origins
Although the origins of the art have been debated for several decades, it is generally accepted that Tang Soo Do was originally a Koreanized version of Japanese Karate, and that the Moo Duk Kwan style originated as a combination of three major styles: Yang Tai Chi Chuan, Northern China and Southern China Kung Fu, combined with the Okinawan/Japanese discipline of Karate and its modified Forms by Grandmaster Hwang Kee (黄琦 / 황기) (1914 - 2002).


Name
Tang Soo Do is the Korean pronounciation of the Hanja characters 唐手道, which in Japanese are pronounced "Karate-Do" (way of the Tang Hand). The first recorded usage of the term "Tang Soo Do" in contemporary history was by Chung Do Kwan founder, Won Kuk Lee . Prior to the unification of the "Kwans" under the Korea Taekwondo Association, most of the major Kwans called their style Tang Soo Do. The Chung Do Kwan, along with the rest of the Kwans ceased using the name Tang Soo Do when they unified under the name Taekwondo (and temporarily Tae Soo Do) The Moo Duk Kwan, however, remained independent of this unification movement, and continued to call their style Tang Soo Do. Over time, this lead to Tang Soo Do and Moo Duk Kwan essentially becoming synonymous in the modern martial arts world.

In 1995, the late Hwang Kee officially changed the name of the Moo Duk Kwan style to Soo Bahk Do.


Founder
Unlike most contemporary martial arts, it is not possible to pinpoint any one person as being the "founder" of Tang Soo Do. One could argue that Won Kuk Lee "founded" the style, being the first (known) person to use the name, however that argument would be dubious, at best. However, the Moo Duk Kwan style of Tang Soo Do (where nearly all modern Tang Soo Do stylists trace their lineage to) can be traced to a single founder: Grandmaster Hwang Kee. Hwang Kee was said to have had learned Chinese martial arts while in Manchuria, and had been influenced by Japanese Karate, and the indigenous Korean arts of Taekkyon (택견)and Subak. He also claimed to have been highly influenced by an old book about martial arts called the Muye dobo tongji (武藝圖譜通志 / 무예도보통지).


Current State
With the change of the Moo Duk Kwan style to Soo Bahk Do, Tang Soo Do Moo Duk Kwan, technically ceased to exist. However, Tang Soo Do continues to flourish under numerous organizations, that have at some point in time separated from the Moo Duk Kwan. Tang Soo Do continues to evolve and grow, and in the last two decades has emerged from Taekwondo's shadow to become a well known, and well respected Martial Art in it's own right. Many Tang Soo Do practitioners claim that Tang Soo Do continued to follow the path of a "Traditional" martial art that they feel that Taekwondo more or less abandoned in its push for Olympic Games inclusion.