to Chinese Siege Warfare
3rd August 2005
China is a land steeped in history.
For thousands of years, China as a country and the Chinese as a people have grown and developed a rich civilisational heritage of art, philosophy, culture, traditions, language, exploration, science and, warfare. Dominating the Eastern corner of the Eurasian continental landmass, the entity that became known as China surged and ebbed with the expansion and contraction of dynastic cycles and from the pressures of external invasions and civil wars. Chinese history could record relatively few lengthy periods of peace, littered as it was with wars between Warlords, Generals, Kings, Emperors, Sons of Gods and every other combination of aspirants for the celestial throne.
Over in the Middle East, the Assyrians (1170-612 B.C.) were among the first civilisations to create a systematic and methodical strategy for besieging fortified cities. Assyrian siege strategy required that cities be reduced and conquered quickly. Details shown in reliefs of the siege of Lachish showcased their siege technology, which ranged from the basic scaling ladders to the tank-like tower/rams. Much of this knowledge spread into the rest of the Middle East and onward into the classical civilisations of Greece and Rome.
China at the time of the Assyrians was a chaotic period full of incessant warfare between rival states. With the power of the Zhou Imperial Court weakened and with its role relegated to merely figurehead ceremonial functions, the various states within the empire rose to take advantage of the power vacuum in a fierce armed struggle for dominance over each other. Hegemons and warlords ruled the land.
The Spring and Autumn period (770-476 B.C.) as recorded in the "Spring and Autumn Annals", was a time of great innovations. Competing philosophies vied for attention, new ideas emerged and a classic arms race escalated between the various states. From the writings of two Han scholars Jia Kui and Xu Shen, we already found possibly the earliest mention of a stone throwing machine called Hui, a word that no longer exists today, in a war between the King of Zhou and the rebellious Duke of Zheng in 707 B.C.
By the time of the Warring States period (475-221 B.C.), when the numerous small states of the Spring and Autumn period had been whittled down to seven dominant major states of Qin, Qi, Chu, Wei, Han, Zhao and Yan, Chinese siege techniques, already known to have reached a rather sophisticated form, took on an increasingly prominent role in the interstate wars of the period.
Much of what we now know of siege technology of the Warring States period came to us from Mozi Books 14 and 15 (Chapters 52 to 71) on Siege Warfare, a Mohist text written at about the 4th - 3rd century B.C. Recorded and preserved on bamboo strips, much of the text is now unfortunately extremely corrupted. Despite the heavy fragmentation however, many segments containing the early records of siege techniques and siege weaponry could still be discerned and through teasing out the information on these segments, we were able to piece together our earliest pictures of Chinese siege warfare during the turbulent Warring States period.
Where did these techniques for siege warfare come from? Some authors have suggested that there was possibly a diffusion of technology from the Assyrians. The chariot for example, is known to have come from the early civilisations of Mesopotamia. Did a similar transfer of knowledge occur in the case of siege techniques and know-how?
Assyrian siege technology was a relatively late development of the 8th-7th century B.C. Assyrian empire, a period which corresponded with the beginnings of the Spring and Autumn period. The Sunzi's Art of War, believed to have been written in the 6th century B.C., had writings that already show elements of siege warfare, notably Chapter 3 on Preparations for War. By the 4th century B.C., in the writings of Sun Pin's Military Methods, there was a reference though fragmentary, to a possible use of catapults as defensive artillery. The writings of the Fan Li Bingfa or Fan Li's Art of War of either the Warring States or early Han period, listed a machine which threw 12 jin (2.6kg during the Han dynasty) rocks 200 paces.
It is certainly possible that the techniques and ideas spread across the intervening centuries from the Assyrians into China, but the relative closeness in dates and the isolation of pre-Silk Road China from every other early civilisation would suggest a high degree of parallel indigenous development as well. This is especially true of the siege catapults and arcuballista of the late Spring and Autumn period and Warring States period. Heavy artillery in Assyrian siege warfare was conspicuously absent from excavated reliefs and surviving records of the period.
Various interesting snippets of both defensive and offensive measures came to us from historical accounts. Chinese sieges used many innovative forms of both offensive and defensive methods. Throughout Chinese history, it wasn't uncommon for instance, for an attacking army to dam up a river and flood the whole area to make the fortified city an island in the middle of a man-made lake a few metres deep. Even water-rams were used by diverting whole rivers to batter down walls and doors. The technologies and methods used were very advanced and innovative for their time such as the Mohist use of echo-location to pinpoint enemy tunneling, the employment of poison gas pumped through bamboo pipes by bellows to kill enemy miners, and specialised assault boats and troops to storm enemy dikes built to hold static water pressures to crumble city walls. The Mohists also wrote about the sinking of deep holes approximately 100m down to the levels of the aquifers to siphon off flood waters. In one particular defence, stretched silk/cloth wetted and coated in mud for fire-protection, was tightened and stretched across the front of the city gate to act as a vertical trampoline to bounce the attacker's battering ram right back at them. In besieging a city, counter-wells were sometimes sunk to draw down the water table so as to deny water to a besieged city's wells. Conversely, in order to secure water supplies, bamboo pipes were known to have been used as water pipes to bring water down to the cities from mountains. The city-end of the pipes were heated to create the necessary initial suction and gravity did the rest.
Early Chinese siege weaponry and techniques had aided in the victory of the Qin state over its rivals, and brought a close to the Warring States period. In the records of the Grand Historian, Sima Qian's Shi Ji, written a century after the Qin, it was written that Qin Shihuang, the First Emperor used a siege crossbow to kill a sea monster. The Qin artillery drew on the myriad forms of the earlier Warring States period but the exact form remains illusive. No evidence of siege weaponry to date has emerged from the excavations in the Terra-cotta museum in modern day Xian. It has been opinioned that the winch mechanism of Qin era arcuballistas differed from the better known Song arcuballistas, drawn instead through a pumping action of ratcheted winches. Nevertheless, whatever its form, this triumph of military arms had extended the borders of the Middle Kingdom well beyond the limited boundaries of the traditional heartland of the Central Plains. Using these artillery pieces to good effect, the Qin subdued, conquered and consolidated large tracks of what is now China proper, marching troops as far south as the coast of modern day Guangdong Province.
Strangely enough, we found little mention of siege weaponry right after the demise of the Qin and in the succeeding Han dynasty. The Han dynasty (206 B.C.-A.D. 220), further extended the borders of China, establishing the first official military outposts along the narrow northwestern corridor of what would eventually be known as the Silk Route. Investigations of the writings from the highly fragmented bamboo-strip Shoufa Shouling Shi San Pian, a manual on siege warfare from the Han dynasty, revealed a reference to a mobile weapon called the Ji (or Jie) Che “Plough Cart”, with a 50bu (75m) range, spaced on top of defensive walls at intervals of 200bu (300m) for 5-crew versions and 50bu for smaller 3-crew versions:
With a relatively short 50bu range, this Ji Che might have been a small traction catapult and not an arcuballista, as ranges for even the smallest arcuballistas would had easily exceeded this distance. The use of the word Bei (Cup) might refer to the use of a scoop instead of a sling to seat a projectile, and fired in a seesaw-like motion. This perhaps even explained the word “Plough” in the name. However, as there was no further information available to be gleaned from the bamboo-strips, the workings of this mobile catapult remained elusive.
In the Huai Nan Zi ca. 120 B.C. we found a description of a Wu Gang Che or “Military Strong Cart”, one of the few references to Han era field artillery:
From the Han Shu or Records of the Han one more reference stood out, in Li Ling's campaign of 99 B.C. for the possible use of a Han era arcuballista. Beleaguered and harassed in a fighting withdrawal deep in nomad country, Li Ling's army used what seemed to be wagon mounted crossbows in a defensive formation to defend against the attacking Shanyu cavalry. The early formative years of the Han surely must have employed great numbers of siege machines of some sort but to date, there is scant evidence of such in written records and none in Han era excavations.
One theory that might account for this sudden disappearance is that the Han, unlike the combative states of the Warring States period, had little need for large siege weapons. The borders of the Han neighboured empty nomad steppe lands and vast deserts. This forced a more mobile style of warfare onto Han commanders and instead of sedentary siege techniques we see the development of lager type infantry squares as temporary defenses and an emphasis on highly mobile cavalry in an extremely early version of maneuver warfare, helping project Han military might beyond the garrisoned borders of China.
The breakdown of Han authority in the 2nd century A.D. saw yet again a rise of warlords and increasingly independent and powerful states. The transition of Han into the period of the Three Kingdoms of Shu (Han), Wei and Wu again revitalised the need for siege weaponry and techniques. From the Sanguo Zhi, or Records of the Three Kingdoms period, we read descriptive accounts of battles occurring throughout central China. Of significance is the shear number of sieges recorded in the account, and the siege strategies employed by the various commanders and generals. Fighting raged throughout the empire, from the fortified towns of the central plains to the many fortresses that guarded the numerous strategic passes that so dominated Chinese warfare strategy. Evidence of new forms of siege technology such as the forked assault cart to pull down fortress walls and the development of the multiple bolt arcuballista appeared in this new arms race of the post-Han period. One particular innovation was that of Liu Ye and Cao Cao at the Battle of Guandu where they fitted wheels to catapults to turn them into Pili Che "thunderbolt wagons”.
In a typical and classical city siege of the period, Zhuge Liang of Shu (Han) attacked Chen Cang with 40,000 troops in the twelfth month of A.D. 228. Attacking from all four sides, mobile ladders were used, manned by archers to pour covering arrow fire down on the wall defenders while portable ladders and ropes were used to ascend the walls. However, the defenders led by Wei commander Hao Zhao retaliated with incendiary arrows and repulsed the assault. Undaunted, Zhuge Liang attempted yet again with mobile assault wagons only to be thwarted by large stones lashed together and hurled by defensive catapults. Raising the ante, earthen mounds were then built only to be countered yet again by the defenders raising the height of their interior walls. Frustrated with the lack of progress, Zhuge Liang then ordered clandestine tunneling to undermine the city walls in the area of his earthen mounds to hide the evidence of earth movement. However, again defensive measures, in the form of transverse trenches, cut to intercept the approaching miners, countered his efforts. Eventually, low on provisions, Zhuge Liang withdrew after 20 days of intensive fighting which showcased the height of siegecraft of the Three Kingdoms period.
Crushing Shu (Han), the northern Wei ended the era of the Three Kingdoms period, only to be usurped from within by the Western Jin. The Western Jin went on to unify China under the new dynastic banner of the Jin with the conquest of Wu in A.D. 280. However, despite achieving unification, weakened from centuries of civil war the empire soon came under the traditional external threats from the north and northwest which successive dynasties continued to attempt to stem and subdue but with limited success.
Splitting and retreating southward, the long succession of rival dynasties in the North and South of China spawned the development of new methods of warfare, tactics and technology. Advances like the stirrup had made possible the increased use of heavy cavalry by rival armies. The chaos of the next few centuries saw new and major improvements in the catapult and arcuballista as well.
Unity under the Sui in A.D. 581 saw the advent of a stabilising China after centuries of warfare. The Sui engaged in a fever of major infrastructure development works especially in the digging and development of the Grand Canal linking the traditional northern administrative heartlands of China with the productive agricultural south, as well as in the building of a new “Great Wall” south of the older Qin dynasty Great Wall.
Despite having achieved a high level of sophistication in siege technology by the time of the Sui, ill advised and costly campaigns by the Sui to reverse the retreat of Chinese territories lost over the last few centuries especially into the northeast, coupled with the impact of mega project building soon doomed the dynasty into rebellion yet again. This set the stage for yet another change in the dynasty cycle, a mere 36 years after unification.
The Tang inherited the mantle of the Sui mega projects and unity of the Chinese heartlands. Building on the foundations of the Sui, the loss of Chinese dominance over the peripheral territories far from the central plains was reversed with the ascension of the Tang in the 7th century A.D. allowing for the expansion of the Tang dynasty back into the former boundaries of the earlier Han and an almost complete dominance of the entire East Asia. After an initial century-long burst of expansion, a relative period of stability prevailed.
This lull at the height of Tang power saw a plateauing of siege engine science and development, not challenged until the turning point event of An Lushan's rebellion in A.D. 755 to 763. From this point onward till the fall of the Tang in the early years of the 10th century A.D., we saw a marked shift from the early Tang military expansions to internal infighting within China proper as rebellions and increasingly independent provincial governors defied the weakened central government. Increasingly, towns were again refortified and fortified forts sprung up in the countryside to dominate as well as to provide a defense in depth for major cities. This change from frontier military actions along the periphery of the empire to the sedentary need to assault fortified cities and bring provinces back under central control saw an expansion in siege techniques and new forms of siege weaponry especially in increasingly large traction catapults.
The Tang siege of the rebellious Huai Xi Province of A.D. 815-817 proved a case in point on the effectiveness of these fortified towns and forts as this relatively minute province withstood the brunt of five Tang armies from all sides for three long years. Surprisingly though, little account of direct sieges of these fortified positions were found in the records perhaps because most battles were fought in highly mobile strikes and counter strikes in the open fields. This destructive infighting persisted even after the fall of the Tang, into the chaos of the Five Dynasties and Ten Kingdoms period.
Unifying the empire once again in A.D. 960 under a single banner, the Song dynasty inherited the innovations and advances in technology from the preceding chaotic era, and further developed them in a period of rapid innovation fueled by the duality of a rising northeastern threat from the steppes and increasing maritime tradelinks with the early kingdoms of a rising Southeast Asia.
The Song era was a hotbed of new ideas, especially in the new and exciting field of gunpowder weaponry. From the 10th to the 12th centuries A.D., innovation and development in Chinese siege warfare escalated. Threatened by the predatations of the increasingly aggressive northern peoples of the Jin, Liao, Xia and Mongols, whilst supported by the increasingly profitable southern maritime trade, the arms race rose to a feverish pitch. However, by the 12th century A.D. the Song dynasty, unable to hold back the tide of aggression, was forced to flee from its northern lands and retreat south of the Changjiang (Yangtze River).
Fortifying itself along the river, the Southern Song dynasty fought the invaders to a standstill. New technologies were churned out ranging from paddlewheel warships of up to 23 wheels, to landmines and double-staged naval rockets in an effort to keep the invaders at bay. During the Jurchen siege of Xiangyang of A.D. 1206-1207, the Song commander for the Xiangyang defense, Zhao Zun built an additional 98 catapults to bolster the original 16 catapults mounted on the city walls. These catapults, placed on the wall tops or in defilade inside the walls ranged in type from the rotating Xuanfeng to the heavy 9 or 10 bundled lever catapults. The latter must certainly have been mounted on Sijiao frames.
Chen Gui, co-author with Tang Shou of the Shoucheng Lu or “Defense of Towns” who was an active participant and therefore a direct eyewitness of the earlier siege of De An in A.D. 1127-1132, recorded that the largest type of catapult had a pulling crew of 250 with two men to a pulling rope and had levers of 2.8 chang long (somewhat between 6 to 9 metres during the Song) while the smallest single levered catapults required a crew of 40 men pulling on 20 pulling ropes. The ranges obtained from these catapults were also recorded where he gave the ranges for Song era large and small catapults. Large first class catapults had a range of 270 bu, second class catapults 260 bu and third class catapults 250 bu, while the small single-levered catapults could hurl 1 kg stones up to a distance of 50 bu (where a bu at the time of the Song was approximately 60 centimetres). It was also during this time when the term Huo Pao or Fire Catapult arose. This term did not, as some have been led to believe, refer to a type of gunpowder cannon but was simply a catapult that hurled incendiary projectiles or gunpowder grenades.
For almost one and a half centuries of bitter but stalemated fighting, the Song held the Mongol invaders at bay and occasionally, by sallying forth northward to try and recapture the Central Plains, threatened to turn the tide against the invaders. It was only after the Mongols overran the Middle East that the next leap in siege technology tipped the scales in favour of the Mongols against the beleaguered Song in the final decades of the 13th century A.D.
Since A.D. 1268, having frustratingly besieged the stubborn Song-held twin cities of Fancheng and Xiangyang for four long and arduous years two Persian Engineers were brought in to break the deadlock. By building their new hinged counterweight catapults, the Mongols now had the means to defeat the Song. In an epic artillery struggle that ensued between the two bitter foes, each side pummeled the other with bombs, boulders and all manner of projectiles. With time running out, the Song Emperor ordered that an attempt be made to rescue the besieged garrisons. A relief force of a hundred Song paddlewheel warships led by Generals Zhang Shun and Zhang Gui, ran the deadly gauntlet of Mongol catapults to try and break the siege. These highly maneuverable ships, formed into a rectangular formation were armed with traction catapults, firelances, crossbows and bombs. With red signal lanterns and under cover of darkness, they broke through the Mongol artillery barrage to deliver their supplies. However, the effectiveness of the new Mongol weapon inflicted a heavy toll on the Song navy, sinking ships and killing many onboard the surviving ships, including the two bold Generals in charge of this naval fleet. Despite the supplies brought in at such great a cost, the rescue proved too little, too late. Unable to adapt their own catapults quickly enough, the twin cities fell after a prolonged bombardment of Fancheng in A.D. 1273. The Song dynasty crumbled a mere six years later.
The introduction of the Persian hinged counterweight catapult into the battlefields of China proved to be the straw that broke the camel's back for the unfortunate Song dynasty. Despite having an early lead in the promising new field of gunpowder based weapons the Song dynasty proved powerless to counter the raw power of the new Mongol weapon.
The Mongol Yuan dynasty, consolidated its grip on China, and drew Engineers and craftsmen from across the vast empire of the 5 Khanates. This intermingling by the Yuan and by the other 4 Khanates helped mix and spread new ideas and technology across the entire Eurasian continent. However, despite the technological advantage enjoyed by the Mongols, their vast holdings did not hold, collapsing yet again into chaos by the mid 14th century A.D.
In East Asia, local uprisings throughout China challenged the foreign rulers for the Mandate of Heaven, resulting in bitter fighting for control of the fortified cities of the central plains and especially up and down the Grand Canal and the Changjiang. This period also saw significant use of inland navies between the major combatants with fighting occurring along the Changjiang and its tributary lakes. One of the major innovations from this period was the direct assault of riverside cities by large multi-deck ships. The river navies of this early period used bridges and gangplanks extended directly from the top decks of their ships to put troops onto city walls. This prompted the shifting of city walls away from the river's edge to create a buffer zone.
In A.D. 1360-1363, three major combatants for the control of China in the wake of crumbling Mongol Yuan power, the Han, the Wu and the Ming, were in full conflict. At the siege of Nanchang just prior to the famous naval battle of Boyang Lake, the Han under Chen Youliang had besieged the Ming garrison. Cannon or other siege engines must have been present because the first Han assault opened a gap of over thirty chang in the city wall which was only refortified by the defenders with a new palisade of wood and earth after very intense fighting between the two combatants. Bogged down at Nanchang and eventually trapped on Boyang Lake, where the smaller and more nimble Ming ships were able to take advantage of the shallower depths as well as maneuver into upwind positions for their fire catapults and cannons, the Han naval might was soon smashed and its remnants incorporated into the Ming armies. This round of intensive fighting was eventually whittled down to one sole winner, giving rise to the next dynasty, the Ming.
The armies of the Ming dynasty were characterised by the gradual adoption of increasingly powerful gunpowder based cannons, guns and rockets. However, Zhu Yuanzhang who inherited the Mandate of Heaven as the first Ming Emperor was quick to praise his old catapults that were so vital in his campaigns against his rivals. In A.D. 1388 he was recorded to have said:
Nevertheless, the change over to gunpowder was inevitable at the close of the 14th century A.D. When Grand Admiral ZhengHe sailed his treasure fleets in his seven great voyages of trade and discovery from A.D. 1405 to A.D. 1433, his ships carried these new weapon systems. Cannons, rockets and guns armed his warships, some of which measured more than 400 ft long as he carried Chinese naval power, pushing back pirates and establishing trade and forward bases from the southern Chinese coast to the east coast of Africa. ZhengHe's first voyage was a fleet of 317 ships with 27,870 men, which included not only sailors but also soldiers, merchants, diplomats, clerks, administrators, interpreters, artisans, weaponsmiths, doctors, astrologists, chartographers and meteorologists.
This increased reliance on gunpowder by the Ming dynasty revolutionised siege warfare and pushed the great siege catapults and arcuballistas of traditional Chinese artillery into obsolescence. The last records of Chinese mechanical artillery in action must probably have been the Ming expeditions south into Annam ca. A.D. 1421, when Chinese Huihui Paos were fired alongside gunpowder guns and cannons. A century later, during General Qi Jiguang's fight against the marauding Wokou pirates of the mid 16th century A.D., gone were the siege techniques and weapons of the previous two millennia. New offensive strategies and defensive fortifications were adapted and modified to suite the new queens of the battlefield.
Ming dynasty China was also a period of increasing contact with the West which was fast catching up. Flush from an age of intensive exploration and expansion 60 years after the voyages of the Grand Admiral, European arms soon overtook those of China. European cannons opened the way for much of Western colonisation and trade, resulting in an unprecedented change in the traditional relationships and politics of China with her neighbours as the Chinese sphere of influence shrank.
The Manchu Qing dynasty, which replaced the Ming by the 17th century A.D., reversed the shrinking sphere of influence in the early years of Qing rule. Chinese territories reached its furthest extent under the Qing. The Qing however, failed to realise the threat of the increasingly sophisticated industrialisation of the West, and Chinese weapon technology faltered going into the 19th and early 20th century A.D.
Qing artillery and arms were proven time and time again to be woefully inadequate and inferior to those of the Western powers despite many attempts to modernise and upgrade. This left China open to predation. Repeatedly humbled, these failures cumulated in a series of unequal treaties which the Qing were forced to endure. Weakened and ripe for a fall, the reign of the Qing ended in A.D. 1911 after a series of popular uprisings planned, engineered and led by Dr. Sun Yat Sen from his support base in the Overseas Chinese communities of Nanyang. The new republic of Dr. Sun inherited a sad state of affairs. The state of Chinese military science, once the technological marvel of East Asia if not the world, had by that time fallen so low that the army of the new Nationalist Republican government was little more than an infantry force with almost nonexistent heavy weaponry and artillery. This has led many today to believe that Chinese armies throughout history were poorly armed human-wave peasant armies, an ignorance that persists and continually serves to propagate the myth.
For millennia, Chinese armies dominated their rivals by having superior weaponry on their side. So successful was this dominance in arms that the early rapid growth and expansion of the Chinese sphere of influence and control, was halted only by physical geographical barriers such as the mountain ranges of the Tibetan Plateau, the deserts and grass steppes of the northwest and the Pacific Ocean to the east. Since the early years of Chinese civilisation, warfare has been an integral part and parcel of life. Much of this was fought in the mountain passes, the fortified towns of the open plains, the river gorges, the open steppes, the vast deserts, the long convoluted coastline, and in the varied and rugged geography of the Chinese heartland. The rise and development of Chinese siege technology was but one facet of Chinese warfare, but one no less important in the continuous struggle of the Chinese to survive as a people and as a political entity. The drive to innovate and to gain the upper hand over rivals, both within the country as well as outside, pushed Chinese military Engineers to dazzling heights of excellence. Reaching a technological peak in the late Song dynasty, the devastation of the Mongol invasion and the Ming and Qing dynasties' inability to compete in the new gunpowder arms race with the new threat from the West proved the undoing for a proud Chinese tradition in siege warfare, much of which remains sadly unknown and unacknowledged to this day.