As with most ancient practices, there are legends around origins of TaiChi and there are multiple versions of it. But everything leads to a legendary Taoist monk Zhang Shanfeng creating a set of practices to fight off robbers in a remote Chinese province several centuries back. Taoism was a way of life created by the great master Lao Tzu over 15 centuries back and recommended the principle of gentleness, moderation, simplicity, balance and spontaneity. All of these principles are intertwined into the practice of TaiChi. One idea that will encompass all of this is the great parable of flowing water. When water is constantly flowing without stagnation, it can build up great strength and energy and even the greatest dikes cannot stop it for ever- though it seems so gentle and fragile. So, Taichi recommends gentle flowing motion just like water.. and keep up the movement and never be still in one position.
Back to the story, Zhang Shanfeng's practices became better and better, but nobody else knew about it, till he started participating in national martial arts competitions and defeated several expert fighters using his unique technique. He taught the practice of TaiChi only to his family members and they built a reputation of being unbeatable in fights. Several people wanted to learn this unique technique, but the master did not accept any students and struck to practicing with his family. One determined student somehow got into the family house as a servant and learnt the art by secretly watching the family members practice. It was this servant that then spread the practice to the public - leading to TaiChi now being practiced by over 2 billion people the world over. Who knows what the actual history is.. but this is a very interesting legend indeed!
There is also the great legend of the original master observing a crane fight a snake so gracefully, that he was inspired to imitate it's movements and created the practice of TaiChi. As you start practice, you will realize how several TaiCHi movements resemble a crane spreading it's wings and opening up in full alertness. The crane balancing in one leg is also significant. In majority of TaiChi moves, 70% to 90% of the body's weight rests in one leg and the other leg is always light - ready to move and step in any direction required. So, this crane opening it's wings in full glory, balancing in one leg and fighting a snake in complete alertness is a great depiction of the art of TaiChi