In the famous battle of Changping in 260 BC, Qin’s commander, Bo Qi, “allowed Zhao’s forces to advance in the center, encircled them on the flanks, cut their supply lines, and seized the fortifications they had left behind.” Giuseppe Rava
The great battle of Changping, though more geographically concentrated than the preceding campaigns, involved two armies deadlocked across a front that stretched for hundreds of li [borough, administrative unit between the township].
The light cavalry soon became a prime means for launching “unorthodox” battlefield tactics. For instance, the Sun Bin lists ten benefits: “reaching strategic points before the enemy, attacking undefended spots, pursuing fleeing soldiers, cutting supply lines, destroying bridges or ferries, ambushing unprepared troops, taking the enemy by surprise, burning stores and pillaging markets, and disturbing agriculture or kidnapping peasants. In short, cavalry were employed in skirmish, reconnaissance, ambush, and pillage.”
Seven powers strove to seek hegemony in the Warring States Period. Besides using military force, each state also resorted to political and diplomatic means. The six eastern states joined hands to form a south-north vertical alliance to confront the State of Qin, called the “vertical alliance.” Meanwhile, the State of Qin, located in the west, took advantage of the conflicts among the eastern states, and tactically went into collaboration with part of the six states and finally attacked all of them one by one, called a “horizontal collaboration.” The eastern states sometimes followed the State of Qin and sometimes followed the State of Chu for the sake of their own interests. Some advisors, like Su Qin and Zhang Yi, traveled around the states, persuading vassals to adopt a vertical alliance or a horizontal collaboration and were called “Men of Alliance and Collaboration.”
Qin efforts to occupy the Central States incurred some failures, which prompted dynamic internal reforms in response. Zhao strengthened its position by opportunistically forming alliances to expand at the expense of Wei and Qi. In 269 BC a Qin army was dispatched to put a stop to Zhao’s expansionist aggression, but the Qin forces were soundly defeated. This debacle was followed by a shake-up at the Qin court, leading to the rise of the very capable minister Fan Sui and bolstering the position of Fan’s political ally, the great general Bo Qi. Under Fan Sui, King Zhaoxiang of Qin centralized the government so that individual commanderies and counties headed by bureaucrats reported directly to him. This undercut a “new aristocracy” that had begun to appear in Qin in the century since Lord Shang’s reforms. The aristocracy, consisting of a number of successful military leaders, had been rewarded with huge grants of land. Besides governmental reform, military strategy was also provided with a larger vision beyond opportunistic raiding and annexation of territory. Fan Sui offered instead a policy of deliberate conquest, picking off other states one by one, annihilating their ruling classes and armed forces, and taking total control of their territory by subsuming it into Qin’s bureaucratic and more efficient government structure.
The crucial test of this policy came with the Battle of Changping in 260 BC. Qin tried to annex some territory belonging to Hann (Zhao’s ally at the time), but this was resisted by Zhao. In the battle that followed General Bo Qi lured the Zhao army into an exposed forward position, encircled it, and settled down to starve the Zhao forces into submission. After several weeks the Zhao general, Zhao Kuo, made a desperate but unsuccessful attempt to break out. The Qin forces butchered his entire army, supposedly 400,000 men. But the Qin victory at Changping came at a cost. The Qin army had also suffered substantial casualties in the battle, and Bo Qi advocated resting his armed forces for a while. His advice was rejected, and he committed suicide under duress. When a Qin expeditionary force was slaughtered shortly thereafter while attempting to take the Zhao capital, Fan Sui was cashiered, accused of treason, and executed in 255 BC.
Overall, classical texts record more than 1.5 million deaths among Qin’s targets in major battles between 356 and 236 BC. Rough estimates of battle death figures include the following: 7,000 Wei soldiers in 354 BC; 45,000 Wei soldiers in 330 BC; 82,000 allied troops of Han, Wei, and Zhao in 317 BC; 10,000 Han soldiers in 314 BC; 80,000 Chu soldiers in 312 BC; 60,000 Han soldiers in 307 BC; 20,000 Chu soldiers in 300 BC; 20,000 Chu soldiers in 298 BC; 240,000 Han and Wei soldiers in 293 BC; several hundreds of thousands of Chu soldiers and civilians in 279 BC; 40,000 Han soldiers in 275 BC; 40,000 Wei soldiers in 274 BC; 150,000 Wei and Zhao soldiers in 273 BC; 50,000 Han soldiers in 264 BC; 450,000 Zhao soldiers in 260 BC; 20,000 Chu and Wei soldiers in 257 BC; 40,000 Han soldiers in 256 BC; 90,000 Zhao soldiers in 256 BC; 30,000 Han soldiers in 245 BC; and 30,000 Wei soldiers in 244 BC. These battle death figures, which served as the basis for military rewards, are likely to be “biased upward.” Lewis 1999, 626. The most controversial figure is the burying alive of 400,000 Zhao soldiers in Changping in 260 BC. Archaeological evidence indicates that a great battle was fought on the site, but there is no evidence for a massive burial of 400,000 men. However, Hsu thinks that the number is “not necessarily incredible” and Gao finds “no basis to reject it.” Gao 1995, 435; Hsu 1965a, 67. Sawyer believes that Warring States battle death figures may be “less inaccurate than thought” because “states of the period were certainly capable of mobilizing a very high percentage of their male population, particularly when threatened with extinction.” Sawyer 1998, 559, fn. 38. Lewis concurs that ancient Chinese figures “present a consistent picture of an expanding scale of military actions that fits well with what we know of the evolving institutions and practices of the period” and are “not wholly out of line with what we know of the size of armies that primarily live off the land.”