What are the origins of Four-Pillar (BaZi) Astrology?

Four-Pillar astrology (also called Zi Ping or BaZi) is the result of ancient Chinese ideas about the unity of heaven and humanity combined with the Yin-Yang and Five-Elements (Wu Xing) framework, applied to life prediction. Its origins and development are deeply rooted in Chinese civilization.

Development and core evolution:
• Early beginnings (before the Han): Early fate views emerged. People observed celestial phenomena (planets and constellations), used turtle-shell divination (oracle bone inscriptions), and applied the hexagrams of the I Ching to glimpse destiny, but a systematic personal prediction method had not yet formed.
• Tang dynasty foundations (classical methods): The figure traditionally known as Li Xuzhong (attributed author of the Li Xuzhong Mingshu) centered analysis on the year pillar and introduced Na-Yin based Five-Element reasoning; this older approach emphasized ancestral influence and macro fortunes and is often called the “three-life” or “Lu-Ming” method.
• Song dynasty maturation (modern system established): Xu Ziping (author of Yuanhai Zhiping) made a pivotal change by adding the hour pillar to year, month and day, creating the complete four-pillar system. Most importantly, he shifted the analytical focus to the Day Stem (the day-master), representing the individual. He formalized the use of the five elements’ cycles of generation and control, and introduced the Ten-Gods social-role model (Officer, Resource, Wealth, Output, etc.), greatly improving precision. This marks the birth of the contemporary BaZi system, often referred to as Zi Ping.
• Later development: During the Ming and Qing dynasties many classic works appeared (e.g., San Ming Tong Hui, Di Tian Sui, Zi Ping Zhen Quan) that refined concepts such as configurations (zheng guan, shang guan, etc.), the choice of useful elements (yongshen), likes/dislikes (xi/ji), and other detailed techniques, producing a highly nuanced body of knowledge.