Battle of Chengpu

Infobox Military Conflict
conflict=Battle of Chengpu
partof=the Spring and Autumn Period


caption=
date=632 BC
place=vicinity of Chenliu County, Henan or the southwest of Juan County, Shandong
casus=
territory=
result=Decisive Jin victory
combatant1=States of Jin, Qi, Qin, Song
combatant2=States of Chu, Chen, Cai, Shen, Xi
commander1=Hu Mao, Hu Yan, Xian Zhen, Xi Zhen, Xu Chen, Luan Zhi
commander2=Ziyu, Zishang, Zixi
strength1=700 chariots (Jin),other parts unknown.
strength2=Unknown
casualties1=Unknown
casualties2=Unknown, 100 chariots and 1000 warriors captured

The Battle of Chengpu (城濮之戰) was a conflict between the states of Jin against Chu and its allies in China in 632 BC during the Spring and Autumn Period. It could be viewed as the first great battle in the protracted conflict between the states of the Yellow River valley, and the states of the Yangtze River (Chang Jiang) valley. The Jin victory confirmed the hegemony of Duke Wen and checked Chu ambitions in the north for at least a generation.

Background

Following the death of Duke Huan of Qi in 643 BC, the state of Chu steadily extended its influence northward and had been absorbing half a dozen smaller states as its satellites. In 636 BC, Ji Chong'er, a ducal prince of Jin, came into power and was named Duke Wen of Jin with the help of Duke Mu of Qin after having spent fifteen years in exile traveling throughout numerous states. Duke Wen assumed a position of leadership among the states and instituted numerous domestic reforms. In the years leading up to 632 BC, conflict between Jin and Chu was increasingly public and was characterised by frequent shifts in alliances between the various small states that lay in a band between the two giants.

In the winter of 633 BC, King Cheng of Chu struck at Song, the ally of Jin most accessible from the south. In retaliation, an expeditionary force under Duke Wen marched south in the spring of next year and occupied Wei and Cao, both satellites of Chu. Both sides sought out alliances in the following months. The states of Shen, Xi, Chen, Cai, all immediately contiguous to Chu, sided with King Cheng, as well as the more distant Lu.

Prelude

Jin is said to have retired "three stages" (45 km) before camping on the plain of Chengpu at the border of Wei and Cao, awaiting a decisive battle and thus fulfilling Duke Wen's promise to King Cheng during his refuge in Chu. The retirement also linked the Jin forces up with Qi and Qin reinforcements.

Only the central force of the Chu under supreme commander Ziyu was made up entirely of Chu troops. The left wing under Zixi incorporated soldiers from Chu's close satellites Shen and Xi. The right wing under Zishang comprised completely a separate detachment from the armies of Chen and Cai, perhaps numbering around a third (?) of the entire force.

The Jin force was expanded before the expedition from two armies into three: the upper, the central and the lower; these three were then regrouped into wings before the battle: the upper army at the right wing under commander Hu Mao and vice-commander Hu Yan, lower at left under Luan Zhi and vice Xu Chen, central remained at centre under Xian Zhen and vice Xi Zhen. Duke Wen did not direct or engage in the fighting.

Battle

On the fourth day of the fourth month of 632 BC, the rival forces met.

The battle commenced with the advance of both wings of the Jin army. The Chu right wing was reckoned to be the weakest and Xu Chen, commander of the Jin left wing, attacked. Xu armoured his chariot horses with tiger skins and launched an urgent, vigorous assault on the Chu right wing. The attack was rapidly successful, scattering and demolishing the enemy wing completely.

The Jin left then became holding force, fixing the Chu center and preventing it from attacking the Jin centre or aiding the Chu left wing, since in either case the Jin left would have taken it in the flank and rear. Meanwhile Hu Mao's Jin right wing had skirmished with the enemy, faked a retreat and carried with them the two great banner of the Jin commander-in-chief himself. The Chu left, made up of levies from Shen and Xi, thought that the Jin right wing had lost and Ziyu ordered a pursuit. A contingent of chariots under Luan Zhi swept in front and dragged tree branches, raising a dust fog to obscure the movements of Hu Mao's men who were circling and reforming.

The Jin left continued to maintain position against the Chu center, and was aided by the Jin center. Though the Jin centre was temporarily disordered by an intense whirlwind, it was effective in preventing the Chu center from supporting its left wing. As the Chu left advanced, it was caught in the flank by Duke Wen's bodyguards, composed of the sons of noble clansmen and sons of his close followers and thus flanked by the Jin central army. Meanwhile the entire force of the Jin right wing completed its recircling and was supported on its right by Luan Zhi's chariots to join the assault. The Chu left was completely destroyed. Seeing both his wings enveloped, Ziyu ordered a general retreat.

Evaluation

The Battle of Chengpu is probably the biggest of the Spring and Autumn Period and definitely the most detailed in the "Zuo Zhuan". Nevertheless the location of the battle remains obscure: two inconclusive possibilities are the vicinity of Chenliu County, Henan and the southwest area of Juan County, Shandong. After returning to the north, Duke Wen was recognised by the King of Zhou as first among the feudal lords. A multi-state conference at Jiantu in 631 BC headed by Duke Wen confirmed their support for the Zhou royal family and swore a covenant of alliance. The battle, however, was not effective in the long term in restricting the power of Chu.