Muaythai is the devestating "science of 8 limbs" from Thailand
developed over 1000's of years.
The exact date of the creation of this fighting art is not known but it is widely believed to be over 2000 years old. Many other martial arts are believed to be this ancient though many of them were only created in the last 100 years (Aikido, Taekwondo, Karate).
Muaythai used to be referred to as Pahuyuth (multi-faceted fighting style) a couple of hundred years ago, but muaythai itself is only a part of the whole Thai fighting system that covers weapons and groundwork which many refer to as Ling-Lom, though this is not the correct name for it. Many people do not know about this "no holds barred" of muaythai and there are very few people that can teach it.

The Thais are a tribal people and have had to defend their country from many invaders throughout their history. It has been developed year by year passing from teacher to student for as long as the Thais can remember. Muaythai is often referred to as the science of eight limbs as it employs not only punching and kicking techniques but elbows and knees as well.
It could be said that Muaythai currently is split into two parts, the ring sport and the martial art. The art side contains many techniques that cannot be performed in a ring with gloves on.