Military history of China before 1912

The recorded military history of China extends from about 2200 BC to the present day. Chinese pioneered the use of crossbows, advanced metallurgical standardization for arms and armor, early gunpowder weapons, and other advanced weapons, but also adopted nomadic cavalry and Western military technology. China's armies also benefited from an advanced logistics system as well as a rich strategic tradition, beginning with Sun Tzu's The Art of War, that deeply influenced military thought.

The military history of China stretches from roughly 1900 BC to the present day. Chinese armies were advanced and powerful, especially after the Warring States period. armies were tasked with the twofold goal of defending China and her subject peoples from foreign intruders, and with expanding China's territory and influence across Asia.

Early Chinese armies were relatively small affairs. Composed of peasant levies, usually serfs dependent upon the king or the feudal lord of their home state, these armies were relatively ill-equipped. While organized military forces existed along with the state, few records remain of these early armies. These armies were centered around the chariot-riding nobility, who played a role akin to the European knight as they were the main fighting force of the army. Bronze weapons such as spears and swords were the main equipment of both the infantry and charioteers. These armies were ill-trained and haphazardly supplied, meaning that they could not campaign for more than a few months and often had to give up their gains due to lack of supplies. The shi knights had a strict code of chivalry. During the Shang and Western Zhou eras, warfare was seen as an aristocratic affair, complete with protocols that may be compared to the chivalry of the European knight.

Under the Shang and Zhou, these armies were able to expand China's territory and influence from a narrow part of the Yellow River valley to all of the North China plain. Equipped with bronze weapons, bows, and armor, these armies won victories against the sedentary Dongyi to the East and South, which were the main direction of expansion, as well as defending the western border against the nomadic incursions of the Xirong. However, after the collapse of the Zhou dynasty in 771 BC when the Xirong captured its capital Haojing, China collapsed into a plethora of small states, who warred frequently with each other. The competition between these states would eventually produce the professional armies that marked the Imperial Era of China.

Early Bronze Age Chinese cities were characterized by massive defensive walls. The Erlitou culture's bronze workshops probably gave it a decisive edge over competing groups. Armies were probably relatively ineffective given the prevalence of extensive fortifications, although the Erlitou culture probably succeeded in breaching these occasionally since they were able to expand the area of their control. Starting from the 3rd Millennium BC and throughout the 2nd Millennium BC, there is a correlation between elite status and military status in tomb artefacts.

While chariots had been used in battle previously, only in the Western Zhou era were they used in large numbers. The Zhou conquest of the Shang may have been linked to their use of the chariot. Under the Shang, chariots were extremely ornate, used by high ranking elite as command and archery platforms, but under the Zhou chariots were simpler and more common. The ratio of chariots to foot soldiers under the Shang is estimated to be 1 to 30, while under the Zhou it is estimated to be 1 to 10. However this was still limited as compared to the 1 to 5 in Ancient Egypt.

In the Spring and Autumn period, archery switched from targeted shooting to massed volleys. By the end of the Spring and Autumn period, cavalry had appeared on the battlefield, and the chariot would gradually revert to being a command platform in the course of the ensuing Warring States period.

By the time of the Warring States, reforms began that abolished feudalism and created powerful, centralized states. The power of the aristocracy was curbed and for the first time, professional generals were appointed on merit, rather than birth. Technological advances such as iron weapons and crossbows put the chariot-riding nobility out of business and favored large, professional standing armies, who were well-supplied and could fight a sustained campaign. The size of armies increased; whereas before 500 BC Chinese field armies numbered in the tens of thousands, by 300 BC armies regularly included up to a couple of hundred thousand drafted soldiers, accompanied by cavalry. For example, during the Battle of Changping the state of Qin drafted all males over 15 years of age. Although these conscripts with one to two years of training would be no match individually against aristocratic warriors with years of experience, they made up for it with superior standardization, discipline, organization, and size. Although most soldiers were conscripts, it was also common to select soldiers based on specific qualifications. The Confucian adviser Xun Zi claimed that foot soldiers from the Wei state were required to wear armor and helmets, shoulder a crossbow with fifty arrows, strap a spear and sword, carry three days' supply of rations, and all the while march 100 li (41.6 km, based on the Eastern Zhou li) in a day. When a man meets this requirement, his household would be exempted from all corvée labor obligations. He would also be given special tax benefits on land and housing. However, this policy made soldiers in the Wei state difficult to replace.