Zhang Sanfeng is a semi-mythical Taoist master dating from either the late Song dynasty or the Yuan dynasty. His name was 張君寶 before he became a Taoist.
His Taoist name in Traditional Chinese characters is 張三丰, but is usually mistaken as 張三豐. Both are zhang1 san1 feng1 in pinyin and Chang San-feng in Wade-Giles.
Much of the written material about him is mythical, contradictory, or otherwise suspect. For instance, he is reported to have been born in AD 960, AD 1247, and again in AD 1279. He is described as being seven-feet tall, with the bones of a crane and the posture of a pine tree, having whiskers shaped like a spear, and being able to cover 1000 li in a day.
Legend reports Zhang Sanfeng as having originated the concepts of Nei Jia or soft internal martial arts, specifically Tai Ji Quan.
More reputable sources record two chinese emperors sending missions to Zhang Sanfeng to ask for his advice, although neither mission is reported to have found him.
Owing to his mythical appearance, his name frequently appeared in Chinese novels and films of swordsmen as a master of martial arts.
The legend's name was made widespread (perhaps) in the Western Hemispehre through Jet Li's 1992 portrayal of Zhang San Feng and the invention of Tai Ji Quan. This movie was known in China as "太极张三丰" (Tai4Ji2 Zhang1San1Feng1 - Supreme Ultimate Zhang San Feng), though the foreign release was aptly named The Taichi Master. A heavily edited and dubbed US release exists in which Jet Li and Michelle Yeoh (known best for their work in Crouching Tiger, Hidden Dragon) are featured on the box art as being "Twin Warriors". In reality, that title has absolutely nothing to do with the movie with respect to Michelle Yeoh. Nevertheless, the movie contains Kung Fu choreography that some consider to be amongst the best in motion picture history.
