The Battle of Qi and Lu at Changshao-齐鲁长勺之战

After ascending to the throne, Duke Huan of Qi decisively defeated the invading forces from Lu, compelling Lu to kill its prince, consolidating his rule. He appointed Guan Zhong as his prime minister, and under Guan Zhong’s assistance, Qi experienced significant development in politics, economy, and military. Duke Huan, observing the stability and prosperity of Qi, with a strong military, decided to launch a military campaign against Lu to avenge the previous year’s dispute over Prince Jiu’s position and expand Qi’s influence. However, Guan Zhong, believing the time for dominance had not come, advised Duke Huan to focus on internal governance, build diplomatic ties, and patiently await the right moment. Duke Huan, impatient for dominance, dismissed Guan Zhong’s counsel.

In the spring of 684 BCE, Duke Huan led an army to attack Lu, invading its territory.

Both Qi and Lu were important vassal states during the Western Zhou period. Lu, with its capital at Qufu (present-day Qufu, Shandong), governed the southwestern part of present-day Shandong and adhered to the traditional rituals and music system of the Zhou society. By the Spring and Autumn period, it was only a second-tier vassal state. In contrast, Qi, the fief of Duke Taigong, an eminent figure during the founding of Western Zhou, had its capital at Linzi (present-day northeast of Zibo, Shandong), encompassing a vast area in the northern part of Shandong. With fertile land and abundant resources, Qi, under the leadership of its rulers, pursued effective development policies, resulting in economic prosperity and substantial national strength. By the Spring and Autumn period, Qi held a pivotal position among the vassal states. Lu was in a disadvantaged position compared to Qi in both territory and national strength.

A year prior to the events, Lu, after a severe defeat by Qi, intensified military training, produced various weapons, and initiated internal reforms to gain the people’s trust. When Duke Huan led the Qi army close to Lu’s border, Duke Zhuang of Lu decided to mobilize the entire nation to resist the Qi invasion. With Qi having a strong and motivated army that had previously triumphed over Lu, Duke Zhuang withdrew the Lu forces to the strategically favorable location of Changshao (north of present-day Qufu, Shandong).

As Duke Zhuang prepared for battle, a man named Cao Ci from Lu requested an audience with Duke Zhuang to offer military advice. Cao Ci, possessing both strategic insight and political foresight, approached Duke Zhuang with the determination to save the country.

Cao Ci asked Duke Zhuang, “What do you rely on to fight against Qi?” Duke Zhuang replied, “Things like clothing and food, which sustain life, I dare not hoard for myself but share with the people.” Cao Ci responded, “These are just minor favors and cannot benefit the entire populace. When the people are risking their lives in battle, such gestures won’t inspire them.” Duke Zhuang said, “During sacrificial ceremonies, I am sincere and honest, never daring to falsify the quantity of offerings.” Cao Ci remarked, “This level of sincerity may not necessarily move the deities, and they might not bless you.” Duke Zhuang continued, “For minor disputes among the people, even though we may not be able to discern every detail, we must handle them within the bounds of reason, ensuring that no one suffers injustice.” Cao Ci then said, “In performing these duties, you fulfill the responsibilities of a sovereign. The people can follow you, and we can go to battle.” Cao Ci immediately volunteered and requested to accompany Duke Zhuang to the battlefield.

Duke Zhuang and Cao Ci proceeded to the battlefield at Changshao together. In ancient China, battles followed certain rituals: both armies would align in formation, advance after drumbeats, stop after fifty steps to reorganize, and repeat this process until the armies engaged in direct combat, creating a chaotic situation.

After both armies formed their formations, Duke Zhuang witnessed Qi forces attacking Lu’s positions and was ready to issue the order to counterattack. However, Cao Ci advised against it, stating that Qi’s soldiers, with their morale at its peak after the first attack, would become weaker with subsequent assaults. Duke Zhuang, following Cao Ci’s counsel, ordered Lu forces not to attack but to defend their positions with archers. Qi soldiers, unable to break through the defense and facing arrows, had to retreat. After regrouping, Qi launched a second attack, but again, Cao Ci urged Duke Zhuang not to counterattack immediately. Qi’s morale waned, and they withdrew once more. Qi’s commanders believed that Lu forces, intimidated by their strength, were reluctant to engage. Consequently, Qi initiated a third, grand attack. After the first two assaults, Qi soldiers were already fatigued, and their morale had declined. However, Lu forces maintained a strong formation and high morale. Cao Ci, seeing the change in the battlefield dynamics, believed it was the right time for a counterattack. Duke Zhuang, inspired by Cao Ci’s analysis, personally beat the war drum, ordered an attack, and Lu forces, highly motivated, overwhelmed Qi, forcing them into a retreat.

After the victory, Duke Zhuang ordered a pursuit of the retreating Qi forces. Cao Ci, however, advised Duke Zhuang not to rush the pursuit. Cao Ci then got off the chariot, observed the battlefield, and only after ensuring Qi’s defeat, allowed Duke Zhuang to issue the pursuit order. Lu forces, motivated and relentless, chased Qi forces out of their borders, capturing numerous soldiers and supplies, achieving a decisive victory in the Battle of Changshao.

After the triumph, Duke Zhuang couldn’t resist discussing with Cao Ci the reasons for the war’s outcome. Cao Ci explained that in war, courage plays a crucial role, with the first charge being the most vigorous, followed by a decline in subsequent charges. Regarding the delay in counterattacking, Cao Ci reasoned that Qi was a powerful state, and a hasty pursuit might fall into an enemy ambush. He pointed out the disorderly state of Qi’s forces by observing their flags and weapons and the chaotic tracks left by their chariots, concluding that they were genuinely defeated. Duke Zhuang, convinced by Cao Ci’s insights, nodded in agreement.

The Battle of Changshao between Qi and Lu, though not large in scale, showcased valuable ancient military strategies, reflecting the fundamental principles of defensive victories for weaker armies against stronger ones. The battle, occurring between Qi and Lu, had significantly different outcomes, emphasizing the triumph of justice over injustice, even in ancient times when warfare relied on melee weapons.