Section from the painting Portraits of the Emperors by Yan Liben. (Ink and color on silk.) Emperor Sui Wendi is pictured in the right foreground and is followed by his son and successor Emperor Sui Yangdi. Wendi and Yangdi were the only emperors of the short-lived (thirty-seven-year-long) Sui dynasty.
Military campaigns—against the Chen to reunify north and south China, against Turks north of the Great Wall, and against Koguryô in Korea—dominated much of the Sui dynasty (581–618 CE). Legal and administrative reform, infrastructure improvements, engineering marvels, and construction of cities and palaces were hallmarks of the period. The dynasty ended after only two emperors.
The Sui dynasty lasted only thirty-seven years, from 581 to 618 CE, and had only two emperors, Sui Wendi and Sui Yangdi. A hallmark of the dynasty was territorial expansion. The dynasty began with Wendi’s successful campaigns to reunite north and south China under his rule; the dynasty ended when the huge loss of life and wealth caused by Yangdi’s failed campaigns to expand into Korea incited rebellion and overthrow. Wendi began legal reforms and the building of a large imperial library that Yangdi continued. Both emperors built grand new capitals and improved and extended China’s infrastructure of canals, roads, and the Great Wall. Administrative reforms, such as the creation of civil service exams, strengthened imperial bureaucracy at the expense of the aristocracy and provincial officials.
Reunification of North and South China
The crowning achievement of the Sui dynasty was the reunification of China, ending nearly three centuries of division between Southern and Northern dynasties (220–589 CE). Sui Wendi acceded to the emperorship of north China by usurping his grandson. Almost immediately after his enthronement on 4 March 581, Sui Wendi turned his attention to the problem of “swallowing the region south of the Yangzi River,” that is, conquering the Southern Chen dynasty (557–589 CE) that ruled the region. On 28 March, he took the first step toward realizing his ambition by appointing two of his most successful generals to posts as Governor-Generals for regions on the Yangzi (Chang) River’s northern bank. But the emperor had to delay preparations for the campaign in order to deal with threats from his Turkish neighbors.
The preparations resumed in earnest during 585. The most urgent need for the Sui campaign was a navy. The Yangzi River was a formidable obstacle, forming a natural barrier that the Chen relied on for defense against attacks form the north. The southerners had established eight fleets along the river’s course to thwart Sui invasions. On 6 September 585, Wendi appointed Yang Su (c. 561–606), his most able commander, to the post of Governor-General for Xinzhou (on the Yangzi in southwestern Sichuan), with instructions to construct a fleet. The emperor supplied him with two million yuan in cash, one thousand lengths of silk, and two hundred horses to accomplish the task. The most impressive craft that Yang built were large warships, each of which had castles of five stories that rose more than one hundred feet above their deck and could accommodate eight hundred men. On the prow, stern, starboard, and port, the general installed six spiked booms fifteen meters tall that pivoted down to strike enemy ships. During a battle the booms dropped vertically onto opposing vessels to damage or pin them. Yang Su also constructed a large number of troop transports with room for one hundred naval soldiers each.
On 22 November 586, Wendi appointed his third son Yang Jun (570–600) nominal head of a temporary government that had control over thirty-six districts on the Han River, a northern tributary of the Yangzi. The emperor charged him with building a second navy. The prince’s staff gathered a force of soldiers, sailors, and marines that exceeded 100,000 men. Wendi also had a third maritime fleet constructed and stationed in the Yellow Sea off modern Haizhou in Jiangsu Province. This fleet was under the command of Admiral Yan Rong (fl. 557–604), who earned an unenviable reputation for cruelty.
To solve the problem of supplying a large military force with provisions, Wendi undertook the construction of the Shangyangdu, a canal that linked the Huai River to the Yangzi. Its completion, on 15 October 587, enabled the Sui to ship materiel and provisions to the front faster and cheaper than over land. In the same year one of Wendi’s commissioners procured 100,000 horses to serve as mounts for his cavalry and as teams for supply wagons.
Another prerequisite for launching the campaign against the Chen was the subjugation of the Liang dynasty, a small state sandwiched between the Han and Yangzi rivers. Its ruler came to pay homage to the Sui court on 25 September 587. Wendi took advantage of the monarch’s absence from his state and ordered one of the Sui armies to attack the Liang capital. On 25 October, it encamped outside the city’s walls, and the following day the Liang court along with 100,000 men and women fled into Chen territory.
The order of battle was fixed on 22 March 588, when Wendi issued a decree calling for an eight-pronged assault on the south with three navies, the two armies the emperor had established in 581, and three additional forces—one under the command of his son Yang Guang (later emperor Yangdi)—that he created later. Altogether he had 518,000 men under arms who faced some 100,000 Chen warriors. The main objective of the campaign was to seize Jiankang (modern Nanjing), the Chen capital.
The war began in late 588, when Yang Su’s navy of several thousand ships sailed down the Yangzi through the Three Gorges and encountered a Chen fleet of one hundred vessels at a set of rapids. During the night the general led his ships past the white water while his marines seized two strongholds on either side of the river. Yang Su pursued the retreating Chen forces downstream, where he ran into three iron chains strung across the river to prevent the passage of his fleet. Again Sui marines attacked Chen forts, carried them with the loss of five thousand troops, and removed the chains. In the next engagement Yang sent four of his huge warships against the enemy fleet. They destroyed a dozen or more of the Chen vessels with their spiked booms and scattered the remainder. Afterward the general sailed east, sweeping aside all opposition, and joined forces with Prince Yang Jun at the mouth of the Han River. By that time Jiankang had fallen, and the combined force took no further action. Meanwhile Admiral Yan sailed up the Yangzi where he captured a strategic city.
While the navies were maneuvering on the Yangzi, Sui armies invaded Chen. One of Wendi’s generals had sold old horses to purchase two sets of boats. He hid the set of new, fit boats in inlets along the northern bank of the Yangzi. He moored the set of broken-down craft on the river in full sight of the enemy as a ruse to convince them that his troops could not possibly make a crossing. Under the cover of darkness on the night of 22 January 589 (the lunar New Year), some contingents of the army landed on southern bank of the Yangzi and established a foothold. Sui forces then poured across the river and crushed Chen armies in several battles. On 2 February, they seized Jiankang and overcame the Chen emperor.
Afterward Wendi had Jiankang razed to the ground and converted it into farmland so that it could not serve as a focus for resistance by Chen loyalists. Yang Su put dow
n the last of the southern rebellion in 591. The conquest of Chen extended the borders of the Sui empires to the South China Sea, adding 130 districts and four hundred counties to its territory.
Actions on the Frontiers
The Turks, nomadic tribes inhabiting the steppes north of China, posed the greatest threat to the Sui dynasty. During the Northern Zhou dynasty (557–581 CE), the Turkish Empire, which controlled the region from modern Manchuria to the borders of Persia, was strong enough to exact tribute in the amount of 100,000 lengths of silk a year from the Chinese emperor. In the summer of 582, the Turks launched incursions into northwest China on such a massive scale that Wendi had to station an army across the Wei River from Daxing, his capital, to prevent them from sacking the seat of his government.
One of the Sui dynasty’s responses to the depredations of the alien nations on their frontier was to strengthen the Great Wall, the traditional barrier erected to protect the sedentary agricultural population of China proper from its nomadic pastoral neighbors. In 581, Wendi ordered fifty thousand laborers to construct or repair it. Wendi undertook larger projects in 586 and 587 when he assigned 110,000 and 100,000 men respectively to work for twenty days on the Wall. In the summer of 607, Yangdi sent a host of one million to build a new section of the wall that was more than 540 kilometers long. Five or six out of ten laborers perished during the twenty days that it took to complete that part of the Great Wall.
The Great Wall often failed to thwart Turkish raids. Fortunately for the Sui, dissension broke out among the nomads. Sometime between 582 and 584, the western tribes of the Turkish empire split from their eastern brethren. War frequently broke out between the two divisions of the empire. After a serious invasion that threatened Daxing in 601 and an attack in 602 on Qaghan Qimin (also called Khan Qimin, reigned 599–611 CE), the Sui’s puppet who occupied the steppes between the Huang (Yellow) River and the Great Wall, a revolt by one of its tribes forced the western Turks to withdraw. As for the eastern Turks, a split at court over the question of succession to the khanate arose in 582, and the Sui skillfully played one faction against the other thereafter. In 597, Wendi forged a marriage alliance with Qaghan Qimin by presenting him with a Chinese bride. The emperor also provided him with military support that enabled the khan to defeat his rivals. Thereafter the khan became a compliant servitor to the Sui throne. Further serious problems with the Turks did not arise until 615.
The Tuyuhun, a proto-Tibetan nation that occupied grazing lands around Lake Kokonor on the western frontier, also made periodic incursions into Chinese territory. In 608, they requested assistance in their struggles with the Turks, and Yangdi sent an army out to help them. Intimidated by the size of the Sui forces, the Tuyuhun fled. The Chinese commander captured their commander, took more than a thousands heads, and enslaved four thousand men and women. The Sui then took possession of Tuyuhun territory (some 2,200 kilometers from east to west and 1,000 kilometers from north to south), established local administrative districts, and populated the territory with criminals sentenced to exile for their offenses.
The Sui also engaged in three military adventures to the south, east, and northeast, all of which failed. After re-establishing Chinese control over the old Han protectorate in northern Vietnam during early 603, the Sui commander launched an attack on Champa, a kingdom along the coast to the south. His forces defeated the Champa king’s army, captured the capital (near modern Danang), and despoiled its palace. However, disease carried off four or five out of ten soldiers (including the general), so the remaining troops withdrew. The king, who had fled to an island off the coast, recovered his capital. The Sui did not invade his realm again. In 610, Yangdi dispatched an expedition to pacify some islands off the eastern coast of China. His army encountered fierce resistance and apparently lost 80 to 90 percent of its officers and men. The final military interventions were three campaigns prosecuted against Koguryo between 612 and 614.
Centralization of Power
Wendi had only one political model to follow in reforming his government, that of the centralized autocratic monarchy that the Qin dynasty (221–206 BCE) first established in the third century BCE. Since the first century CE, however, power had gravitated to an aristocracy of great families who controlled local governments to the detriment of the emperor and his bureaucracy. Wendi set out to correct the problem by undermining the regional patricians. To that end, he forbade provincial officials from appointing subordinates (thereafter a prerogative of the Department of Personnel in the capital), from serving in their native districts lest they favor their relatives or partisans, from occupying a post in any district where they had served before so they could not build a base of power, and from taking their parents and adult sons with them when they assumed a new office. The emperor dealt a further blow to the aristocracy in 583, when he eliminated genealogy as a qualification for holding office.
Wendi also wanted to ensure the competency of the bureaucracy and root out corruption. To accomplish that end, he limited the tenure of local governors to three years and ordered them to send representatives to the capital three times per year to report on affairs in their districts. The emperor required the officials to undergo a yearly evaluation of their merits and faults by the Department of Personnel; the results of those appraisals were recorded in the men’s dossiers and were instrumental in determining their promotions or demotions, rewards, or penalties. Furthermore, he dispatched inspectors, the eyes and ears of the emperor, to local districts, where they scrutinized the performance of the governors and rated their conduct.
A competent bureaucracy also required a system for selecting talented men. An edict issued in 587 ordered governors of prefectures to recommend three men annually who were worthy of employment in government offices (a total of around nine hundred men per year after the conquest of Chen in 589). In addition, the Sui established three (later four) civil service examinations that evaluated the learning and literary skills of the candidates. Those who passed the oral and written tests received entry-level appointments to posts in the bureaucratic hierarchy.
Substantial revenues were, of course, critical to the Sui’s centralization of government. In 583 the throne discovered that there was widespread tax evasion among its subjects living east of Luoyang. Household registers were the government’s instruments for determining the liability of families, and the easterners had been falsifying them by listing adult males as minors or seniors who were exempt from taxation. So Wendi sent out inspectors to make an accurate head count. As a result, the agents added 1,641,000 delinquent taxpayers to the tax rolls. Another round of inspections conducted in 609 added another 641,000 names to the registers.
Standardization of the currency was another important measure that Wendi adopted to centralize state control over the empire. When he assumed the throne, there were several forms of cash (round copper coins) in circulation. The emperor had new coins minted, a thousand of which weighed 2.75 kilograms. In 583, he sent specimens of them to customs barriers with orders that officers there were to confiscate any coins that did not conform to the samples and melt them into copper for the state’s use. By 585 the older coins disappeared. The new currency no
doubt had a very salutary affect on trade. Unfortunately, during Yangdi’s reign the government lost control of minting of the coins, and it slipped into private hands. Not only did the weight of coins drop to half and then to a quarter of the original standard, but also manifold currencies appeared, such as iron, leather, and paper coins.
One facet of Wendi’s drive to reform the government was the revision of the legal code. Deliberations ordered in 581 resulted in the elimination of three forms of capital punishment (hanging, dismemberment, and exposure of the condemned’s head in the market), leaving throttling and decapitation as the only legitimate types of execution. The new code also substituted beating with a rod for flogging with a whip. Two years later, the emperor promulgated the Kaihuang Code, which reduced the number of articles (1,537) in the Zhou legal code of 563 to five hundred and arranged them under twelve headings. The Kaihuang Code is no longer extant, but it was the basis of the Tang Code that had the same number of headings and 501 articles. The Tang Code remained virtually unchanged until the Ming dynasty (1368–1644) and served as the basis for the legal codes of Korea, Japan, and Vietnam.
The limitation of capital punishments to throttling and decapitation did not apply to cases of treason. Twice Yangdi had men—a son of Yang Su along with ten of his party and a general who defected to Korea—“quintered.” That form of execution involved tying ropes to the condemned’s neck and limbs and attaching the ropes to chariots. At a signal the charioteers simultaneously spurred their teams of horses in five different directions, dismembering and beheading the man. The flesh of the defecting general’s body was also butchered, roasted, and given to court officials who ate it at Yangdi’s command.
Such acts were exceptional. Wendi took great care to ensure that mistakes were not made in imposing capital punishment. The emperor did not trust provincial officials to apply it justly, so in 592 he forbade them from executing criminals until the Court of Supreme Justices in the capital had reviewed their judgments. In 595 he also commanded the justices to report such sentences to him three times for his approval before they issued the authorizations for executions.
By and large the Sui Dynasty was a period of great leniency toward malefactors. From 581 to 615 Wendi and Yangdi issued sixteen Great Acts of Grace. Those proclamations nullified the sentences of all criminals and emptied all prisons throughout the empire.
Libraries and Literature
One aspect of the Sui’s reunification of China was the assembly of a great library to establish the cultural heritage of the dynasty. In 583, Wendi ordered commissioners to hunt for books that were missing from the imperial library. According to his stipulations, agents were to borrow the books and compensate their owners with one roll of silk for every scroll of text. When the works arrived at the capital scholars selected the best versions and collated them, weeding out forgeries in the process. Then imperial scribes made fair copies, and the originals were returned to their owners. After the conquest of the Northern Chen dynasty, the process continued and contributed to integrating northern and southern cultures.
Yangdi continued collecting manuscripts for the great library. Fascinated with things mechanical, he had a special library constructed in Luoyang for his books. When the emperor visited the library, a maidservant, who preceded him bearing incense, stepped on a trigger device set in the front of the library hall. The trigger activated machinery that raised curtains, swung the two leaves of the door back into the interior, and opened the doors of the bookcases. When he left, the process was repeated in reverse. By the end of the dynasty the capitals had huge libraries. A catalogue compiled early in the Tang dynasty (618–907 CE) listed 14,466 titles in 89,666 scrolls.
In the latter part of his reign, Yangdi was obsessed with conducting three wars against Koguryo, a state in present-day Liaoning Province and northern Korea. The emperor wanted to accomplish what his father had failed to do in 598. In preparation for the campaign he ordered the construction of a maritime fleet on 24 April 611. One of his mandarins went to the northern coast of Shandong peninsula with orders to build three hundred war ships. Workers labored day and night, not daring to rest. Maggots infested them from the waist down, and three out of four perished. After Yangdi arrived at his palace in Zhuojun (near present-day Beijing) on 1 June, he set about marshalling his resources for the war. He called up thirty thousand crossbow men, thirty thousand javelin throwers and ten thousand seamen. To provide ample provisions for his armies, canal barges transported huge quantities of cereals from the granaries on the Huang River to his base in the north. The quantity provided by the barges was apparently insufficient, so the emperor ordered thousands (perhaps 300,000) of two-man wheelbarrows loaded with 180 liters of grain each to make their way up the roads from the south. But before they reached the base at Zhuojun the porters had consumed all of the cereals and fled. Yangdi ordered up fifty thousand carts to carry uniforms, armor, and tents to the front.
By 7 February 612, a host of some 600,000 troops and civilians had assembled at Zhuojun. On 3 March, the first of the armies advanced toward the west bank of the Liao River. On 19 April, the soldiers assaulted a bridge across the waterway, but failed to take it when they met fierce resistance from the Koreans. Yuwen Kai then constructed three pontoon bridges, but he seriously miscalculated the distance. They were 2.4 meters short of the eastern bank. Nevertheless, several contingents leapt into the water from the truncated span and assaulted the Koreans on 24 April. The enemy pushed them back, and three Chinese generals died in the battle. Two days later an engineer fixed the bridges, and the armies crossed the Liao River on them and defeated the Koreans.
Sui forces then laid siege to the stronghold at Ryotongsong (modern Liaodong city). When their repeated assaults failed, Yangdi changed his strategy. He sent nine corps south to attack P’y?ngyang, the capital of Koguryo. That expeditionary force marched to within sixteen kilometers of the city. Realizing that his men were too exhausted to proceed and short of provisions as well, their commander-in-chief withdrew. As the retreating Sui armies were fording a river, the Koreans attacked and inflicted staggering loses on them.
In the meantime Admiral Lai Huer (d. c. 617) sailed from Shandong with his warships. His navy landed on the Korean coast thirty-two kilometers from P’y?ngyang where Sui marines inflicted a crushing defeat on the enemy. Afterward forty thousand troops advanced and assaulted the city. They carried the outer wall, but a counterattack by the Koreans overwhelmed them, slaying or capturing all but several thousand of the marines. The admiral retreated to the coast and waited for the arrival of the northern army. When it retreated, he led his fleet back to Shangdong.
On 26 August, Yangdi’s disbanded his armies. Of the 305,000 troops that had crossed the Liao River, only 2,700 returned. Despite the enormous loss of life and military equipment, Yangdi immediately began preparations for a second campaign.
On 28 January 613, Yangdi called for the mobilization of more troops to invade Koguryô. That announcement immediately sparked disaffection throughout the empire. The first in a series of rebellions broke out five days later, and a further fifteen uprisings erupted before the end of the year. Nevertheless, the emperor dogged
ly persisted in prosecuting the war, and his forces crossed the Liao River again on 21 May. The army besieged Ryotongs?ng for the second time, but failed to capture it after a siege of more than twenty days. Yangdi then ordered one million hemp bags filled with earth to build a ramp 42 meters wide and the height of the city wall so that his troops could ascend and overrun the ramparts. He also had his engineers build siege towers on eight wheels that were taller than the wall. When soldiers pushed them close to the city, archers could shoot into it.
All that effort was for naught. On 25 June, the son of Yang Su, Yang Xuangan, revolted. Xuangan was in charge of the giant granaries at the end of the canal on the Huang River, so his insurrection cut the supply line to the armies in Koguryo. On 6 July, the rebel forces encamped outside an eastern gate of Luoyang, defeated the army sent to oppose him, and breached the city’s outer wall. Making matters worse, one of Yangdi’s commanders defected to the Koreans on 18 July. Yangdi had no choice but to disband the expeditionary army in the north on 20 July. The emperor dispatched one of his generals south to suppress Yang’s rebellion. After the general destroyed the rebel forces, Xuangan ordered his own brother to kill him. On 21 August, Xuangan’s corpse was dismembered in the eastern market of Luoyang. Three days later his remains were butchered and burned. His father’s corpse was exhumed, and the raw bones were burned.
When Yangdi asked for opinions on the question of conducting a third campaign against Koguryo on 14 March 614, his advisors were dumbfounded and dared not offer counsel for several days. Undaunted, the emperor summoned more troops on 4 April, but many of the soldiers did not arrive in time due to rampant rebellions throughout the empire. The army in the north proved ineffectual again, but such was not the case for the navy. Admiral Lai made a third crossing to the Korean coast, and his marines defeated the Korean army. Lai’s men then besieged P’y?ngyang. Y?ngyang (reigned 590–618), the king of Koguryo, was in desperate straits. On 7 September, he pleaded for peace and begged to surrender. Yangdi accepted the capitulation on face value and disbanded his armies five days later.
The Korean king’s surrender was a ploy to buy time. He ceded little territory and no powers over his subjects to his powerful neighbor. When Y?ngyang refused to visit Luoyang to pay homage to the emperor, Yangdi contemplated a fourth invasion of Koguryo, but nothing came of it. The emperor harvested only bitter fruit from his adventures in Korea. Rebellions increased in intensity and ferocity year after year from the beginning of the campaigns until the end of his reign.
Fall of Sui Dynasty
On 19 June 615, Yangdi left for one last tour of the northern frontier. On 6 September, the Chinese wife of Qaghan Shibi, (reigned 611–619), successor to Khan Qimin, sent word that her husband planed to attack the emperor’s entourage with twenty thousand horsemen. Yangdi quickly repaired to Yanmen (north of Taiyuan inside the Great Wall) four days later. On 11 September, Shibi’s warriors surrounded the city. A month later, the Turks lifted the siege when Sui reinforcements arrived on the scene, and Yangdi returned to Luoyang, his capital. The humiliating confinement at Yanmen was the last blow to whatever prestige the emperor had salvaged from the colossal catastrophe of his Korean campaigns.
After his return to the capital, Yangdi obstinately refused to recognize the looming danger, and he became increasingly incapable of dealing with the numerous insurrections that proliferated within his realm. When rebel forces threatened Luoyang in 616, Yangdi decided to flee and to abandon the north. He executed two officials who objected to his flight and set sail on his dragon barge for Jiangdu on 27 August. He languished there for a year and seven months. In desperation he even toyed with the idea of establishing a new capital in the south, but it was too late.
In the morning of 11 April 618, a body of his troops, many of them northerners who ardently desired to return home, stormed the palace, entered its bathhouse, and forced Yangdi into a chair. Aware of his impending doom, the emperor requested permission to take poison wine in an effort to save his dignity, but his captors refused. So he undid his belt sash and handed it to one of the officers who throttled him. Yangdi’s death at the age of forty-nine effectively brought a close to the Sui dynasty, although a grandson reigned over the dynasty nominally as a puppet of the Tang in Daxing for another thirty-six days.
At the height of the Sui dynasty in 609 the empire stretched 5,022 kilometers from the Pacific Ocean to the steppes north of Tibet and 8,000 kilometers from the Great Wall to Vietnam. Within its boundaries there were 190 prefectures, 1,242 counties, and 357,468 square kilometers of arable land and pastures. The census of that year recorded a population of 46,019,956, the largest since the Han dynasty.
In that year the Sui dynasty was a success by any measure. It was at peace with its neighbors. No serious internal insurrections had erupted since 591. A relatively impartial and efficient bureaucracy governed the capitals and provinces. The justice system appears to have maintained order fairly according to a well-defined code of laws, and the country was prosperous. Had it not been for Yangdi’s catastrophic campaigns in Koguryô, the dynasty could well have endured for three centuries instead of three decades.
Source: Benn, Charles D.. (2009). Sui Dynasty. In Linsun Cheng, et al. (Eds.), Berkshire Encyclopedia of China, pp. 2111–2118. Great Barrington, MA: Berkshire Publishing.
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