These 4 ancient sages play different, however very important roles in I Ching history.

Tradition says, that legendary Fu Xi (Fu Hsi) (2953 -2838 B.C.) – ancient sage and later emperor of China - brought I-Ching philosophy to Chinese people for more than 5,000 years. He has created his original 8 trigrams when walking on the bank of Yangtze River and reflecting on eight segments of the shell of giant Chinese turtle (also known as a river dragon). He immediately realized their symbolic value and importance for agriculture. Much later – about the 12th century B.C. - King Wen, being at that time imprisoned in a solitary confinement, created 64 binary images of hexagrams by combining trigrams and re-arranging them in a special way. Originally all hexagrams were created by King Wen without hexagram names and comments for them. Later on he has added names and his explanations (so-called judgments) to each of 64 hexagrams, bringing I Ching to the mainstream. Duke of Zhou (also known as a God of Dreams), the younger brother of King Wen of Zhou, wrote the line comments to each of 64 hexagram. His work produced a first devination-ready version of I Ching making him a cultural hero of China of that times. Finally, about 6th century B.C. legendary Chinese philosopher Confucius (551 – 479 BCE) wrote his famous commentaries – known now as Ten Wings - to the whole I Ching and to all 64 individual hexagrams in it. The I Ching as we know it now was born.