At the lunar eclipse in 1065 BCE, Ji Fa (Zhou Wenwang, better known in the West as King Wen) wrote to his sons from his prison cell. He was expecting a signal from the heavens that Zhou would rule instead of Shang. It was the same signal his father (Ji Li) had been expecting. The eclipse gave King Wen hope that it would occur in his lifetime.

Zhou astronomers knew that there would be another conjunction of the five major planets. To the Chinese, these conjunctions indicated a shift in the fortunes of those on Earth. One of these conjunctions started the Chinese calendar. Another signaled the ascendance of the Xia at the time of Yu. A later conjunction heralded the end of Xia and the start of Shang. That was nearly a thousand years before Wen’s time. The impending conjunction was going to elevate the Zhou.

Is it just a coincidence that King Wen was imprisoned in 1068 BCE, the same year that a new Shang calendar was established? Perhaps Wenwang pointed out some flaws in the calendar, or the newfangled rituals that accompanied it; and that’s what prompted the king to throw him in prison.¹

Challenging the accuracy of a calendar was a form of treason in those days. It’s a wonder Wenwang wasn’t beheaded. After all, he and his father expected a change in the Mandate.

There must have been flaws, because the new calendar apparently failed to account for the lunar eclipse. It was the eclipse that prompted the happy letter from Wenwang to his sons.

Without an accurate calendar, King Di Xin would lose the confidence of the people. According to the Shujing and other sources, the king and his ministers seemed oblivious that Shangdi had turned against him.

The correct orientation of any consecrated space, the scheduling of religious ceremonies, and the proper conduct of seasonal occupations all depended on the king. The ability to comprehend the celestial patterns (e.g., seasonal constellations) and to maintain conformity between astral and terrestrial realms became a fundamental qualification for kingship.²

This crisis echoed the changing of the Mandate from the Xia to the Shang in the Shujing:

[Xia hereditary astronomers] … have violated the duties of their office, and left their posts. They have been the first to let the regulating of the heavenly (bodies) get into disorder, putting far from them their proper business. On the first day of the last month of autumn, the sun and moon did not meet harmoniously in [xiu] Fang. [The astronomers] heard nothing and knew nothing — so stupidly went they astray (from their duties) in the matter of the heavenly appearances, and rendered themselves liable to the death appointed by the former kings.

What does a Mandate look like?

The Zhou rejoiced in 1062 BCE when King Wen was released from prison. The Mandate appeared on 28 May 1059 BCE. Wenwang named 1058 BCE as the year when Heaven’s Mandate was entrusted to the Zhou, and proclaimed himself universal king.

Mozi explained how the Mandate appeared:

A red bird holding a gui by its beak alighted on Mt. Qi, proclaiming: “Heaven decrees King Wen of Zhou to punish Yin and possess its empire.”

— Book 5, Chapter 19

In astronomical terms, the “Bird” (star) held a “gui” (a scepter) in its beak, as it “landed” (set in the west) on Mt Qi in the Zhou homeland.

The Mandate of Heaven shown at 04:30 on 28 May 1059 BCE, viewed in the west landing on Mt Qi. The Bird star is Niao, part of xiu Xing, in the southern constellation of the Red Bird. Xuanyuan is the Yellow Dragon (the spirit of Huangdi, on the "Yellow Road" or ecliptic). The “scepter” is the conjunction. The “beak” appears to be the stars of the xiu Gui (ghost) or Yugui (ghost wagon), which was also part of the Red Bird constellation.

Wenwang moved the Zhou to Feng in 1056 BCE, and released his own calendar. He designed and sited a new capital at Haojing (Xian) a few years later. King Wen died in 1050 BCE at age 79.

Wuwang (King Wu), Wenwang’s son and heir, marched against the Shang on 17 January 1040 BCE, when Suixing (Jupiter) was in xiu Xu (the end of the constellation of the Mysterious Turtle), with a dark moon (that is, around the end of the lunar month).

The Shujing says

On the day wuwu the army crossed the ford of Meng; on the day guihai it was drawn up in array in the borders of Shang, waiting for the gracious decision of Heaven. On the day jiazi, at early dawn, [the Shang King] led forward his hosts like a forest, and assembled them in the wilderness of Mu. … Thus did King Wu once don his arms, and the kingdom was greatly settled. He overthrew the existing government of Shang, and made it resume its old course.

In other words, on the last days of the year King Wu moved his army into place on the north side of the Huanghe at Muye (the wilderness of Mu). The battle of Muye occurred on new year’s day (the first day of Qing Ming or Clear Brightness), with King Di Xin attacking. It was 18 April 1040 BCE.³

Why did King Wu start his campaign at the end of the year, and culminate at the beginning of the next? Because that time was concerned with changes and shifts in political power. Jiao and Sheti, which began the seasons (and the xiu), related to a shift in rulers. The Dragon constellation also signified waxing yang.

When the Mandate shifts to another family, one must be very careful to make a good start.

— Shiji lishu

By all accounts Muye was a vicious, bloody battle. Some of the Shang army turned on itself. King Di Xin was captured and killed.

The victory did not mean the end of Shang rule. King Wu co-ruled with a new Shang king until Wu’s sudden death 2 years later at the age of 54. The Duke of Zhou, as regent, was forced to fight a rebellion of the Shang and members of his own family who had sided with King Wu Geng.

Warfare with the Grand Duke

As explained elsewhere, the position of the "Grand Duke" or Daiyin was important in warfare. The goal was to have the enemy attack the position occupied by Daiyin, which would influence the outcome of events in the defender’s favor.

We know that Suixing was in xiu Xu (Northland, emptiness, darkness) when the campaign began three months earlier. King Wu stopped the army before crossing the Huanghe because his advisors were worried about where Suixing would move.⁴ When the position was favorable they moved across the river. It seems Daiyin was in the south.⁵

When the Zhou army moved into position, it awaited in the location of Daiyin. The Shang would be facing and attacking the baleful aspect of the year when dawn came on new year’s day.

References

1. Aihe Wang. Cosmology and Political Structure in Early China. Cambridge U Press, 2000.
2. David W. Pankenier: “The Mandate of Heaven.” Archaeology 51:2, March/April 1998
3. David Nivision. The Riddle of the Bamboo Annals. Riddle 8 part 1, Riddle 8 part 2. This article uses Prof. Nivison’s timeline.
4. In a new year when the sun and Suixing rise together in a particular xiu, in the February of the next year the sun will rise in the xiu that is just to the east of the xiu of the previous year. The sun rises in the new xiu while Suixing has been there for about a month.
   Zuo Ya. “The Synodic Period of Jupiter in the Chu Silk Manuscript — A New Interpretation of the Sui Chapter.” Selected Papers from Chun-Tsung Scholars. Peking University, 2003.
5. Determined by EquinoX LE software.