Tai Chi, as it is usually called in the west, or Taijiquan, or Taiji Chuan, as it is also sometimes known (precise translation from Chinese is difficult because the language is so different) traces its roots back to a Taoist master called Zhang San Feng (or Chang San Foong). After completing his kung fu training at the Shaolin temple Zhang San Feng took himself on a retreat up the famous Wudang mountain to continue his Taoist quest for immortality. While there he witnessed a fight between a crane and a snake. Inspired by this, he set about modifying his Shaolin kung fu to create softer and more flowing system which emphasised chi training and meditation.
To do this he incorporated his Shaolin qi gong training with his martial arts, and drew inspiration fromt he animals he had seen. This new kind of kung fu was called the Wudang 32 Patterns Long Fist, and is generally thought of as the first of the 'internal' schools of Kung Fu which combine the energy cultivation of Qi Gong / Chi Kung with the external forms of kung fu. Internal, or 'soft' kung fu styles begin with gentle, flowing and soft movements, emphasising harmony, health and the cultivation of chi; in the early stages of learning one of these styles it can be hard to see how it has anything to do with fighting at all, but it is a mistake to think that they are not effective as martial arts. Although it may take many years for a student of one of the internal scholls of kung fu to reach the level where they can apply what they have learned in a combat situation, when they do so they are devastatingly powerful and very effective. There are a number of internal martial arts style in existence today in addition to Tai Chi, such as Bagua Zhang and Xing Yi Quan.
It is very rare to see this original wudang style practiced now, so I will move on to look at the later styles which are still popular today.
The Wundang style was passed on to Wang Zhong Yue, then Zhang Song Xi, and then to Chen Wang Ting, a scholar-general of the late Ming Dynasty. It was this man who founded the Chen style Taijiquan, which is one of the most popular styles practiced today. Compared to the later forms of Tai Chi, which continued the movement away from the original Shaolin kung fu basis towards the 'softer' approach, Chen style Tai Chi is fairly hard and fast, with a noticable resemblance to Shaolin kung fu.
The next development was to the Yang style, a transition attributed to Yang Lu Chan. Up until this point the sectrets of Taijiquan had been closely guarded by the Chen family, who kept it just for themselves. There is a famous story about how Yang Lu Chan was able to learn the Chen style and spread its teachings: Apparently Yang had practiced many different styles of kung fu and was eager to learn the Chen style that he had heard about; he was so eager, in fact, that he gave away his families estate and worked as a servant in the Chen household. While working there Yang secretly watched the family train and practiced what he had learned at night for many years. Then one day another master came to the Chen village to make a Chen Chang Xing, the head of the family and holder of the Chen style. As Xing was too old to fight his eldest son took the challenge, and was badly beaten. The challenger then asked for the master, but his disciples tried to prevent Xing's disgrace by saying that the master was away.
The challenger, however, decided that he would wait for the master to return. It was then that Yang surprised everyone by taking the challenge himself and beating the challenger, restoring the glory of Taijiquan. Because of this Yang was pardoned for his crime of stealing the families secrets by watching them train, and was allowed to go out from the familiy village and practice and teach Taijiquan openly. He travelled all over China to make friendly challenges against all of the kung fu master - and using Chen Taijiquan he defeated them all and became known as the Invincible Yang. Although the Yang style is attributed to him as the one who brought it out of the Chen family it was actually his grandson Yang Deng Fu who modified the Chen style and created what is now known as the Yang style. Yang style Tai Chi is sometimes known as 'big frame' Tai Chi, because it of its large sweeping and open movements, wide stances, and general tendency to make the practitioner open and expand themselves in its practice. Yang style is excellent for health and fitness, and as a combat art is geared towards big powerful moves that would probably suit a large, strong, 'big framed' person.
Wu Yu Xiang established the first of the two Wu styles (pronounced with different pitches in Chinese but with the same translation in English), after learning from two Chen style masters. This style is sometimes differentiated from the other Wu style in English by using the full name of its creator - Wu Yu Xiang. This style has many similarities with the Yang style but with more compact movements and with some of the large sweeping forms replaced with faster and more direct movements. There are also less of the kind of low stances that can be hard work for the legs and joints, and so has a more relaxed feel that is more suitable for the elderly.
The second Wu style, initiated by Wu Chan Yu is concentrates on balance (of different aspects of Tai Chi rather than physical balance!) and harmony.
Then, finally, Sun Lu Tang, at the beginning of the 20th century, combined Wu style tai Chi with two other internal martial arts styles - Bagua and Xingyi, to create the Sun style of Tai Chi. Sun Lu Tang wanted to take the best bits of all three of the internal martial arts he had studied and put them together to create a new martial art. The most noticable benefit of these additions is the advanced footwork of Bagua, which allows its practitioner to change stances quickly and in an elusive manner.
Thus the main forms of Tai Chi today are Chen, Yang, Wu, Wu and Sun styles. Although there are substantial differences between these Tia Chi styles the basic principles are still the same, as are many of the methods.