Traditional Chinese Medicine (TCM) has been around for thousands of years. Although the first recorded history of TCM dates back over 2000 years, it is believed that the origins of TCM goes back more than 5000 years. According to the legend the origins of traditional Chinese medicine is traced back to the to three legendary emperors/mythical rulers: Fu Xi, Shen Nong and Huang Di. Historians believe that Shen Nong and Fu Xi were early tribal leaders. Fu Xi was a cultural hero who developed the trigrams of Yi Jing(I Ching) or Book of Changes. Ancient texts record that "Fu Xi drew the eight trigrams, and created nine needles." Shen Nong, the legendary emperor who lived 5000 years ago is hailed as the "Divine Cultivator"/ "Divine Farmer" by the Chinese people because he is attributed as the founder of herbal medicine, and taught people how to farm. In order to determine the nature of different herbal medicines, Shen Nong sampled various kinds of plants, ingesting them himself for to test and analyses their individual effects. According to the ancient texts, Shen Nong tasted a hundred herbs including 70 toxic substances in a single day, in order to get rid of people's pain form illness. As there were no written records, it is said that the discoveries of Shen Nong was passed down verbally from generation to generation.