The origin of BaZi was founded in Tang Dynasty, about 5000 more years ago in China. As every system in the world has to go through a development period from simple to complex, BaZi has gone through the same way. In the meantime, I Ching was developed as a twin to BaZi.
At the beginning stage, ancestors used I Ching to interpret universe; then they used the Year Stem as the DM, and predicted lives based on the year pillar only. Lee, Xu-zhong (761 ~ 813), the founder, further expended it to 3 pillars – year, month and day. Of course, that was still rough and inaccurate. Later on Xu, Zi-ping (907 ~ 960) during Five Dynasty period finally created the 4 Pillars, putting all the energies from one’s birth year, birth month, birthday and hour together in one chart, and selected the Day Stem as the DM. Because he completed the structure of BaZi, so people call BaZi: “Zi Ping Ba Zi” (or Four Pillars).
Since then, BaZi had formed its own unique system and hundreds of masters in the next couple thousands of years kept making annotations and embellishments to its body, thus almost perfect BaZi theory has been developed with thousands of real life samples for references today. There are many famous masters who wrote BaZi books, just name a few here:
Xu, Zi-shen (Song Dynasty) wrote “Yuan Hai Zi Ping” (meaning: A Sea of BaZi Knowledge)
Liu Ji (1311 ~ 1375, Ming Dynasty) wrote “Di Tian Sui” (meaning Heaven Secretes) – This is the most concise, yet profound, BaZi book. Written by the Liu Ji, (also called Liu Bo Wen) a famous military leader, politician as well as a BaZi guru. By focusing on the five elements, seasonal features, stem and branch characteristics, yin-yang balance, pattern structures, impacts and energy flow, etc., BaZi became sophisticated and much more complete!
Shen Xiao-zhan (Qing dynasty) wrote “Zi Ping Zhen Quan” (The True Meaning of Zi Ping BaZi) with emphasis on Patterns/Structures, the Useful God and Helpful God, and the relationships between the Day Masters and the Patterns, etc.
Yu, Chun-tai (1875 ~ 1908 Qing Dynasty), he wrote “Qiong Tong Bao Jian”. This book has a focus on the details of elemental and Yin-Yang balance requirements by following the 10 Day Master stems’ intrinsic requirements during each of the 12 month.
During the last empire – Guang Xu of Qing Dynasty up to Republic, there was a famous BaZi master whose name is Xu Le-wu (1886 ~ 1949). He wrote many books, including Di Tian Sui with Deep Interpretations and ZiPing ZhenQuan with Interpretations.
And during the Republic Period, there were another 2 famous masters: Wei, Qian-Li, he lived in the northern provinces and Yuan, Shu-San who lived in the southern areas.
Among a dozen of classical BaZi books, the most important 3 are: “Di Tian Sui”, “Zi Ping Zhen Quan” and “Qiong Tong Bao Jian”. Although the contents are rich, but the meanings are deeply hidden. So, without been explained by a teacher, a BaZi learner is very difficult to get deep understandings on those puzzles-filled secrets.