A Native of I-Chou in Liao Tung Province. An external master and court official of the Yuan dynasty (1279-1368), other sources state he was born later in the Sung dynasty (960-1279), who upon retirement retreated with disgust from the world to a Taoist monastery on Wu Tang Mountain, where he acquired his Taoist name of San Feng. He is said to have learned T'ai Chi Ch'uan in a dream, or after watching a bird and a snake fight. More likely, Chang applied the Taoist health principles and knowledge of energy circulation to his vast ability in external kung fu, thus creating something really different - a martial art that dos not use muscle power as a primary source of movement, but Chi. Records available in the monastery on Wu Tang Mountain do indeed mention him. Descriptions picture him as being seven feet tall, with the bones of a crane and the posture of a pine tree (whatever that is supposed to mean), whiskers shaped like a spear, winter and summer wearing the same bamboo hat, carrying a horsehair duster and being able to cover 1000 Li in a day.
The crane - snake combat gave him the ideas that the coiled movement of the snake was like the T'ai Chi Yin Yang symbol and contained the principle of the soft overcoming the hard. Based upon the transformations of the Grand Ultimate, the Yin and Yang leading to the Pa Kua eight Trigrams, the Trigrams leading the 10.000 things (everything), and the Wu Hsing (Five Elements or more correctly changing phases) being the basis of their interaction, he developed Tai Chi Chuan, to gather the Chi, cultivate it to Ching (sexually related living power), and hence transform it into Shen (spirit or divine power); all waxing and waning, movement and stillness, action and non-action embodied in the I-Ching. The most common likeness is to be seen in the White Cloud Temple in Peking.