#ruxu

Ruxu (or Ruxukou) was of vital strategic interest to both Sun Quan and Cao Cao. It was located some 75 miles upstream from Sun Quan’s headquarters at Jianye. It was there that the Ruxu river, flowing south from Lake Chao joined the Yangzi. This formed a harbor capable of housing a significant fleet. Reliable communication between Jianye and Sun Quan’s possessions in the west relied upon his control of the Yangzi. This makes the defensive importance of Ruxu obvious. If Cao Cao could secure it, he would gain three objectives. First, he’d have a bridgehead from which to cross the Yangzi and advance south at will. Second, he would disrupt communications between Sun Quan and his western generals. Thirdly, he would be in a position to advance downriver and attack Jianye itself. This made secure possession of Ruxu a matter of life and death for Sun Quan. Losing Ruxu could very well have meant losing everything.

From Sun Quan’s perspective, Ruxu’s importance was not purely defensive. He was able to house a substantial fleet there. This fleet could, and did, sail up the Ruxu river to Lake Chao. By this method, Sun Quan could rapidly deploy soldiers and supplies for a campaign in northern Yang province, threatening Cao Cao’s positions there. The great fortress of Hefei, built on the northern shore of Lake Chao, was designed to intercept these attacks. As a staging area for Sun Quan’s northern attacks, Ruxu was of irreplaceable value. Should Cao Cao take this position, all efforts to strike north would be considerably more difficult.

These factors made Ruxu a key strategic point, one of the most valuable and coveted positions in the land. The tide of the entire war could turn on its capture.

A NOTE ON RIVERINE WARFARE

Ship-based warfare was never a priority in classical China. Han’s trading partners were primarily terrestrial and vessels had little reason to venture onto the open sea for any extended period of time. Instead, Han merchant ships and warships were designed to operate on the great rivers that have so defined the geography of the nation. Fleets were used primarily to transport soldiers across a river, or to blockade strategic crossings so that the enemy could not do the same.

The technology available to Han armies made it difficult for ships to sink each other. Small projectiles like bows and crossbows did not do significant damage to ships, and most were protected from fire with treated hides. While certain large ships were equipped with small catapults or ballistae, it was extremely difficult to hit a moving target with such ordinance, particularly when the platform holding them is also in motion. This made such weapons of limited effectiveness in ship-to-ship combat.

Instead, most ship-based warfare took the form of boarding parties. Most Han warships were designed for this purpose and there was no separation between terrestrial soldiers and marines. They could be rowed or sailed up to enemy vessels, at which point soldiers would storm the other ship and fight for control. These same vessels could be landed on enemy-controlled banks to discharge soldiers for an attack. So-called “ram-ships” were also employed. These were vessels with a reinforced bow designed to crash into the enemy lines. Unlike their western counterparts, these ships did not possess a sharp ram intended to puncture enemy hulls. Instead, their bows were flat and their purpose was to knock enemy ships out of formation, thereby breaking a blockade and removing obstacles.

All Han dynasty ships relied on a combination of rowers and sails. While Western ships are often defined by the number of sails or oar banks, this information cannot be conclusively determined for Han ships. As a general rule, Han rivercraft favored rectangular, boxy designs rather than the narrow, water-cutting ships of the West. Tang dynasty records discuss six classes of ships. It should be understood that Han fleets were not standardized like those of the Tang dynasty and that many of the warships used during the Han Civil War were converted from civilian craft. With that caveat, these ships deserve some brief discussion.

The largest Han warship was the lóuchuán 楼船. Often translated as “tower-ship”, it was roughly comparable to a frigate. It had three or more tiers and served as a mobile assault tower. The upper tiers usually held archers and sometimes even catapults depending on the size of the frigate. From these raised positions, the archers could reign down arrows or stones on enemy ships or even on shoreline positions. These frigates also carried a large number of boarding troops capable of seizing enemy vessels or securing an occupied riverbank. These powerful ships were an essential element of any complete fleet. However, they were vulnerable to storms. Due to their top-heavy design, strong winds could tip them over.

The standard Han attack ship was the zhànxián (战舷), sometimes anglicized as a brig. This was a two-tiered warship designed to swiftly carry a significant fighting force. They were built for boarding enemy ships and landing on contested shores. A similar ship was called a zǒugě (走舸), often called a barque. These were comparable to brigs in size and function, but they carried more rowers than they did soldiers. This made them faster than the standard brig. To compensate for the reduced fighting power, barques were staffed with crack troops. Their improved speed and the quality of their soldiers meant that barques were often used for sudden raids against enemy positions and for providing emergency relief to endangered ships.

The third ship common to Han fleets was the méngchōng (蒙冲), often called a “ramship”. It was roughly equivalent to a corvette. As the name implies, these ships were designed with reinforced bows for ramming other vessels. They were used for breaking enemy blockades and breaching enemy lines. They weren’t usually capable of sinking other ships through ramming, but the momentum of the ship was sufficient to break smaller obstacles and force other ships out of line. While they were single-tiered, the deck was often used as a platform for archers or boarding troops to attack. The ramships of the Han dynasty appear to have been larger than their counterparts in Tang and later eras, although they were likely the least standardized ships in Han fleets..

While there were other ships in use, such as small patrol and reconnaissance boats and ocean-going vessels, those utilized in active riverine warfare generally fall into the categories above.

A note must also be made about the difficulties of river navigation. Successfully negotiating the rivers of the southern lands was not an easy task. Although there was no appreciable danger of becoming lost, the rivers were long and winding, with many turns and bends. The winds were erratic and storms were to be expected. The uneven riverbeds also presented a danger, particularly to military vessels which rode low in the water. Command of the rivers required an experienced captain who understood the peculiarities of the local terrain and knew how to compensate for the additional weight and awkward distribution of military ships. This was a skill that the southern commanders perfected and which their northern rivals, despite admirable efforts at training, never mastered.

THE FIRST BATTLE (213)

Cao Cao’s first attack against Ruxu was not made in haste. He began preparations for a southern campaign shortly after shattering the Liang rebels in 211. To some degree, these preparations started years earlier. In spring of 208, Cao Cao constructed an artificial lake at Ye so that his commanders could gain some naval experience. This lake remained in use as a center for Cao Cao’s naval drills, although this artificial construction could not offer his men experience equal to that of the commanders who lived among the lakes and rivers.

Among Sun Quan’s officers, it was Lü Meng who first recognized the incalculable importance of Ruxu. When Sun Quan moved his headquarters to Moling (soon renamed Jianye) in 211, Lü Meng urged him to build a large naval base at Ruxu and to fortify both the near and far banks. A number of Sun Quan’s advisers objected to this, viewing the defenses on the far bank as unnecessary and excessive. However, Lü Meng argued persuasively and Sun Quan followed his advice. Thus Ruxu became one of Sun Quan’s most fortified holdings. During the subsequent campaign at Ruxu Lü Meng served as one of Sun Quan’s chief tactical advisers.

Cao Cao likewise recognized Ruxu as the key to victory over Sun Quan. In December of 212, he began an advance southward, with Ruxu as his primary target. In that particular region, a campaign in winter was most advisable. In the other seasons, when the rivers were higher, the defenders had a significant advantage. It was only during winter, when the waters were low, that this advantage was reduced and an attack was feasible.

The respective strengths of these armies are impossible to determine as no precise figures are presented. Cao Cao had the larger army, and his numerical advantage appears to have been significant. Sun Quan sent a request to Liu Bei asking for reinforcements to help defend Ruxu. However, Liu Bei did not send Sun Quan any aid. Instead he used Sun Quan’s plea for help as a pretext to mobilize his army against Liu Zhang in Yi. That Sun Quan would invite Liu Bei’s army into territory he firmly controlled, so close to his own headquarters, suggests that he perceived his situation to be quite precarious. Exactly how large the gulf between Cao Cao and Sun Quan was, though, cannot be estimated.

Cao Cao’s forces reached Ruxu in February of 213. His march towards Ruxu was uneventful aside from one incident. At the outset of the campaign, Cao Cao was accompanied by his trusted adviser Xun Yu, who was given extensive supervisory powers over the army. However, Xun Yu fell ill while on the march and was sent to Shouchun to rest. He soon passed away, and his loss was a blow for Cao Cao’s army. Aside from this, though, Cao Cao’s advance on Ruxu was without conflict. Although Sun Quan nominally claimed a number of towns and villages north of the Yangzi, his men were instructed to fall back to Ruxu instead of offering forward resistance. Instead, Sun Quan put all his strength into defending that key point.

The exact course of the subsequent battle is impossible to determine, but historical records provide several stories from this conflict. It was a furious struggle, with victories and losses on both sides. I have collected these accounts and present them in what seems to me the most logical order of events. However, it is impossible to say with certainty in what order these incidents and operations occurred.

The initial engagement went well for Cao Cao, through a combination of fortune and timing. The mouth of the Ruxu river was guarded by Sun Quan’s renowned general Dong Xi. His biography says that Dong Xi held command from a great five-tiered frigate. This would have served as an effective check against any advance by Cao Cao, as his men would be exposed to extensive fire from archers and even catapults. However, the top-heavy design of this frigate proved to be its undoing. A sudden storm came in the night and the ship began to tip over. Dong Xi’s subordinates fled, but the general himself refused to desert his post. The great frigate capsized and Dong Xi was drowned.

Cao Cao’s biography states that he scored a significant victory at Ruxu. He broke through Sun Quan’s western encampment and even captured his adjutant Gongsun Yang. Most likely, this successful attack followed the unexpected loss of Dong Xi and his powerful ship, which would have provided Cao Cao with an opening. Further, Yue Jin’s biography mentions that Cao Cao made him leader of the vanguard and gave him enhanced authority, so one can assume that he led this victorious assault.

The situation subsequently looked as follows. The Ruxu river flowed north to south, from Lake Chao to the Yangzi, with the Yangzi flowing east to west. Cao Cao’s initial position was north of the Yangzi and east of the Ruxu river. After his victory, he also held the western bank of the Ruxu river. This left the great Yangzi as the obstacle dividing Cao Cao and Sun Quan, with the large harbor of Ruxu as the prize.

Sun Quan’s biography does not provide much detail on the subsequent conflict, but passages appended by Pei Songzhi add more detail. The Wuli says that Cao Cao launched a night attack with light ships hoping to catch Sun Quan unawares. However, Sun Quan was not caught off guard. His own ships intercepted Cao Cao’s and defeated them, capturing and killing several thousand men. In the face of this success, Sun Quan tried to lure Cao Cao out in order to deal him another defeat. He personally rode a light ship in front of Cao Cao’s fleet. Cao Cao’s generals wanted to attack, but Cao Cao saw through the ploy and refused to give battle. After sailing for several furlongs, Sun Quan determined that his plan failed and withdrew.

The Weilüe presents an additional account. It says that Sun Quan took a light boat to observe Cao Cao’s army. He sailed close enough to Cao Cao’s lines to be within bowshot, so Cao Cao ordered his archers to fire at will. The side of Sun Quan’s ship became so filled with arrows that it nearly tipped over. To compensate for this, Sun Quan turned the ship so that the other side was likewise filled. This balanced out the weight, and he subsequently withdrew. This account may be too fantastical to be credited.

The situation at Ruxu became a stalemate. Sun Quan was able to repel Cao Cao’s efforts to cross the Yangzi, but he couldn’t lure Cao Cao out into a vulnerable position and crush him as had been done at Wulin. This stalemate, however, suited Sun Quan well. Once the spring floods came, Cao Cao would be obliged to retreat. The Wuli says that he sent Cao Cao a letter telling him as much and that Cao Cao was deeply impressed by Sun Quan’s courtesy. Regardless of this letter, Cao Cao was certainly aware of the dangers that the spring rains presented. As the month came to a close, the waters began to rise. Having made no headway, Cao Cao decided to withdraw before sustaining any major losses.

So the first Battle of Ruxu came to a close. Although Sun Quan sustained greater losses in terms of manpower and personnel, he was ultimately victorious. Cao Cao’s plans to invade the south were for a second time frustrated on the banks of the Yangzi. However, his losses were minimal and he was fully capable of attacking again.

The next several years were not peaceful ones between Cao Cao and Sun Quan. In the area between the Yangzi and Cao Cao’s holdings in Yang there existed a no-man’s land, deserted by its inhabitants. Both Cao Cao and Sun Quan made efforts to lure the refugees to their side, with Sun Quan having more success. Cao Cao attempted to revitalize this region by installing a capable governor to the city of Huan in Lujiang, but in 214 Sun Quan captured the city and stymied this plan. In 215, Sun Quan used Ruxu as the staging point for a massive assault against Cao Cao’s fortress at Hefei. However, the defenders led by Zhang Liao, Yue Jin, and Li Dian repelled this attack. In between these major battles,  parties from both sides conducted small scale raids along the Yangzi.

THE SECOND BATTLE (217)

In January of 217, Cao Cao began a new campaign against Sun Quan, once again with the objective of capturing Ruxu. He gathered his army at Juchao, upstream of Ruxu. Again, the size of Cao Cao’s army is impossible to determine. Cao Cao claimed to have 400,000 soldiers, although this is obviously an exaggeration. At Wulin, Cao Cao claimed to have twice that number, another figure that is obviously inflated. Zhou Yu estimated that Cao Cao could not have more than 240,000 men. If Cao Cao’s army at Ruxu was half the size of the one at Wulin, it would have numbered perhaps 120,000. This, however, is only a vague estimate based on Zhou Yu’s guesswork and Cao Cao’s own exaggerations. It should not be relied upon as a precise figure. Sun Quan’s army is recorded reliably at 70,000 men, and it is known that he was outnumbered.

Sun Quan personally led the army to Ruxu, but he left tactical command entirely in Lü Meng’s hands. Additionally, Sun Quan gave immediate control of the fleet to Jiang Qin. At that time, the defenses at Ruxu were somewhat in disrepair and needed to be restored quickly. Sun Quan placed his friend Zhu Ran in charge of the repairs, and they were reconstructed before Cao Cao arrived. Zhu Ran was subsequently put in charge of a portion of the defense.

As in 213, Sun Quan’s forward positions gave way before Cao Cao and he reached Ruxu without opposition. As Cao Cao was camped on the riverbank, though, Sun Quan launched an unexpected attack. He sent his general Gan Ning with a small force to lead a raid in the night, and this  attack took Cao Cao totally by surprise. Although Gan Ning inflicted only minimal casualties, this raide greatly demoralized Cao Cao’s forces and energized Ruxu’s defenders.

Gan Ning’s raid wasn’t enough to force Cao Cao’s retreat, though. As before, a storm gripped Sun Quan’s fleet, and a number of his ships were stranded on Cao Cao’s shore. Cao Cao’s men came to attack them, and most of the Wu soldiers were afraid to give battle. They chose to remain on their ships, where they’d certainly be captured. However, the officer Xu Sheng led his men to engage Cao Cao’s shore party. Under his ferocious assault, the detachment retreated and Xu Sheng secured the area. When the storm died down, the ships were able to return to safety. It was only through Xu Sheng’s bravery and valor that Cao Cao was unable to capitalize on this windfall.

Following these events, Cao Cao attempted to force a crossing of the river, where he met with fierce resistance from Lü Meng, Jiang Qin, and Zhou Tai. Lü Meng had stationed an excessively large number of men with crossbows in the defensive towers, and Cao Cao’s vanguard was forced to advance through a hail of arrows, and Lü Meng’s soldiers were always quick to respond to any attack. The fighting was furious on both sides and even claimed the life of Sun Guan, one of Cao Cao’s veteran generals. Due to this energetic defense, Cao Cao’s vanguard was unable to establish a forward position or secure any crossing points.

After several weeks, the weather also started to turn in Sun Quan’s favor. Heavy rains came, along with the seasonal flooding. This left many of Cao Cao’s forward elements isolated and in danger. The situation was so precarious that even Zhang Liao, renowned for his bravery wanted to retreat. The army was held together largely due to the leadership of Cao Cao’s general Zang Ba, who refused to withdraw without orders.

During all of this, illness ravaged Cao Cao’s camp. This was a frequent problem for the northern armies when on campaign in the region. This local illness also played a role in Cao Cao’s defeat at Wulin in 208 and the Wei army’s loss at Ruxu in 223. It was likely a factor in 213 as well. The sickness in 217 was particularly potent, and it appears to have been carried back to Xu and Ye. In Ruxu and at court, this sickness claimed the lives of several prominent figures in Cao Cao’s army. These included Bing Yuan, Chen Lin, Guo Yi, Liu Zhen, Sima Lang, Wang Can, Xu Gan, and Ying Chang .

When the spring floods came, it became clear to Cao Cao that he would no longer be able to capture Ruxu. Faced with this fact, he once again retreated, the whole engagement having lasted for around one month.  However, Cao Cao wasn’t yet finished with his campaign. While Cao Cao himself returned to Ye, he left the majority of the army at Juchao under the command of Xiahou Dun.

This presented Sun Quan with a unique danger. On the one hand, he had proven to Cao Cao and to himself that Ruxu could withstand any attack. But the large army in Juchao severely restricted Sun Quan’s movements. Given the size of Xiahou Dun’s army, Sun Quan could not hope to attack Juchao. On the other hand, any advance he made elsewhere would be under threat from Juchao. This also prevented Sun Quan from repurposing the soldiers at Ruxu for other tasks. Sun Quan’s army was left paralyzed.

On the other hand, it was doubtful that Xiahou Dun could maintain his position indefinitely. Such a large army required extensive supplies and continuously provisioning the Juchao army would be a strain on even Cao Cao’s vast resources. And while Xiahou Dun’s presence was a grave threat to Sun Quan, it also meant that Cao Cao was not free to employ those soldiers against Liu Bei.

After considering the situation, Sun Quan agreed to come to terms with Cao Cao. He formally surrendered, recognizing Cao Cao as the legitimate representative of Han and declaring Liu Bei a rebel. In exchange, Cao Cao permitted Sun Quan to keep control over all the territories he held, nominally as Cao Cao’s subordinate. They renewed old ties between their families and Sun Quan even flattered Cao Cao by suggesting that he become emperor. This surrender was favorable to both parties. It bought Cao Cao temporary peace in the east, allowing him to focus his attentions against Liu Bei, and it secured Sun Quan’s position against further attack. Cao Cao dispersed the army at Juchao and both men were free to pursue other objectives. This ultimately culminated in the two of them joining forces to seize Jing from Liu Bei in 219.

The second Battle of Ruxu was one of the most significant battles of the era, perhaps even more important than the celebrated campaign at Wulin. Old and in poor health, Cao Cao was aware of his own mortality. This battle was his last chance to break Sun Quan’s defenses and conquer his lands. Had Cao Cao been victorious at Ruxu, he could have conquered Sun Quan over the next several years or driven him to a remote corner, making the land’s unification a foregone conclusion.