The legendary figure credited with inventing the Eight Trigrams is Fuxi.
Fuxi, also called Fu Xi or Bao Xi, is a culture hero and one of the Three Sovereigns in Chinese tradition. The Eight Trigrams, or bagua, are traditionally said to have been revealed to him through patterns on the back of a dragon horse emerging from the Yellow River, although some versions describe a tortoise or connect the revelation with the Luo River.
The trigrams are made from combinations of broken and unbroken lines representing yin and yang. Together they symbolize eight fundamental forces or situations in nature: heaven, earth, thunder, wind, fire, water, mountain, and lake. They became foundational to classical Chinese divination and to the I Ching, or Book of Changes.
Fuxi is often confused with later figures associated with the I Ching. King Wen of Zhou and the Duke of Zhou are linked to its judgments and explanations, while Confucian commentators helped shape its interpretation. Fuxi’s traditional role is the originator of the trigrams themselves.