In ancient times there were three Books of Change. Lianshan, also known as Lianshan Yi, is first mentioned in the "Great Diviner" section of the Rites of Zhou. It is attributed to the Heavenly Sovereign. The Rites of Zhou states: "The Great Diviner oversees the methods of the Three Yi: first, Lianshan Yi; second, Guicang; third, Zhouyi. Each has eight primary trigrams and sixty-four derived hexagrams." Lianshan Yi and Guicang Yi have thus become enduring mysteries of Chinese culture. Some believe Lianshan Yi begins with the Gen trigram, like an unbroken mountain range, which is why it is called Lianshan.
Guicang is one of the Three Books of Change, along with Lianshan and Zhouyi. It is said to be named Guicang because its first hexagram is Kun. The "Spring Officials" section of the Rites of Zhou states: "The Great Diviner oversees the methods of the Three Yi: first, Lianshan; second, Guicang; third, Zhouyi. Each has eight primary trigrams and sixty-four derived hexagrams." This means that Lianshan, Guicang, and Zhouyi are three different methods of divination, each made up of sixty-four derived hexagrams formed by combining eight primary trigrams. Lianshan and Guicang are ancient Chinese cultural texts. Some say they were not lost, but renamed as the Earlier Heaven Bagua, the Later Heaven Bagua, or something else.
The Treatise on Literature in the Book of Han says that the Zhouyi took shape as "three sages succeeded one another across three ancient eras." According to tradition, in high antiquity, Fuxi left behind the images of heaven and earth; in the middle antiquity, King Wen of Zhou developed the principles of the Book of Changes; and in more recent antiquity, Confucius and his later disciples wrote commentaries, forming the Ten Wings. The main text and commentaries were eventually combined to form the Zhouyi. The main text consists chiefly of sixty-four hexagrams and three hundred and eighty-four lines. Each hexagram and line has an explanation, known respectively as a hexagram statement and a line statement, for use in divination.
