Lu Su (172–217), style name Zijing (子敬), was a politician, militarist and diplomat serving under the warlord Sun Quan during the late Han Dynasty period of Chinese history. As one of Sun Quan's most important subjects, Lu Su was most noted for having drafted a plan for Sun Quan to compete with rival warlords for supremacy, and succeeding Zhou Yu as the frontline commander of Sun Quan's military after Zhou's death. Lu Su also played an important role in establishing an alliance between Sun Quan and Liu Bei, as well as being a strong proponent of maintaining friendly relations between the two warlords.
Lu Su was a native of Dongcheng, Linhuai. He was born in an affluent and influential clan but no member of his family had ever served in the government before. Lu Su's father died not long after his birth, and Lu Su was raised by his grandmother. When Dong Zhuo usurped state power and caused the government to sink into corruption, Lu Su sold his land and used the money to help his relatives and townsfolk, while spending his time befriending and acquainting himself with people.
In 198 Lu Su came to serve the warlord Yuan Shu and he met and befriended Zhou Yu in the same year. When Zhou Yu had financial difficulties, Lu Su gave him half of the grain he had stockpiled. Zhou Yu later successfully persuaded Lu Su to leave Yuan Shu and serve Sun Ce instead. Lu Su spent a long time in Sun Ce's service but did not receive any important responsibilities.
After Sun Ce's death, Zhou Yu introduced Lu Su to Sun Ce's younger brother and successor, Sun Quan. During their first meeting, Sun Quan was very impressed with Lu Su and held him in high regard, so he dismissed all the other guests also present at the meeting, leaving behind only Lu Su. Sun Quan then invited Lu Su to sit together with him and they had a discussion on politics over drinks.
Lu Su proposed a strategy for Sun Quan to compete with other warlords for supremacy over China - establish a foothold in Jiangdong, attack Liu Biao and seize control of Jing Province (covering present-day Hubei and Hunan), then establish an independent regime south of the Yangtze River. Sun Quan will then declare himself emperor and proceed to attack and conquer the rest of northern China, which was under the control of the warlord Cao Cao. Lu Su's plan was similar to Zhuge Liang's Longzhong Plan in a sense that both plans predicted the rise of three major power blocs in China - Sun Quan, Cao Cao, and Liu Biao in Lu Su's plan; Liu Bei, Cao Cao and Sun Quan in Zhuge Liang's - and also in both plans Cao Cao was seen as the more powerful rival.
Formation of the Sun-Liu alliance
In 208, Liu Biao died and Jing Province was divided between his two sons, Liu Qi and Liu Cong. At the same time, Cao Cao started a campaign to conquer Jing Province, and Lu Su was worried that the province would fall to Cao Cao, thus he urged Sun Quan to form an alliance with Liu Biao's sons to resist Cao Cao. However, when Lu Su arrived in Jing Province, he learnt that Liu Cong (who controlled the northern part of the province) had surrendered his territories to Cao Cao. In Jiangxia, Lu Su met the warlord Liu Bei, who had joined Liu Qi after his defeat by Cao Cao at the Battle of Changban. Lu Su also met Liu Bei's advisor Zhuge Liang, who shared a similar idea of forming an alliance between Liu Bei and Sun Quan to resist Cao Cao. As a result, Zhuge Liang followed Lu Su back to Chaisang (present-day Jiujiang, Jiangxi) to meet Sun Quan and discuss the formation of the alliance.
Sun Quan originally intended to remain neutral and observe the conflict between Liu Bei and Cao Cao while waiting for an opportunity to strike. Besides, he also lacked confidence that his military was capable of defeating Cao Cao's formidable army. After persuasion from Lu Su, Zhou Yu and others, Sun Quan eventually hardened his decision to go to war with Cao Cao. This led to the Battle of Red Cliffs, in which the allied armies of Sun Quan and Liu Bei triumphed over Cao Cao's much larger force.
Role in the Sun-Liu alliance
After the Battle of Red Cliffs, Sun Quan defeated Cao Cao again at the Battle of Jiangling while Liu Bei advanced to conquer four commanderies in southern Jing Province from their respective warlords. Not long later, Liu Bei married Sun Quan's younger sister Lady Sun to strengthen diplomatic ties between the two warlords. Liu Bei requested to use Nan commandery (under Sun Quan's control) in central Jing Province. Lu Su convinced Sun Quan to agree to the request because Liu Bei would help to divert Cao Cao's attention away from Sun Quan to himself.
When Zhou Yu died of illness in 210, Lu Su succeeded him as commander of Sun Quan's military forces and moved his headquarters to Lukou, yielding to Liu Bei all commanderies in Jing Province (except Jiangxia). In diplomatic terms, Sun Quan's side felt that they were "loaning" Jing Province to Liu Bei as a temporary base that should be returned to them after Liu had found another stronghold.
In 215, Liu Bei took over Yi Province (covering the Sichuan Basin) from the warlord Liu Zhang and refused to "return" Jing Province (defended by Liu Bei's general Guan Yu) to Sun Quan. Sun Quan was angered and he ordered his general Lü Meng to invade three commanderies in Jing Province - Changsha, Lingling and Guiyang - while sending Lu Su to fortify his position at Baqiu (present-day Yueyang, Hunan) to block any reinforcements from Guan Yu. After Lü Meng had conquered the three commanderies, Guan Yu indeed advanced south to retake the territories and met with opposition from Lu Su. Lu Su considered the gravity of the situation and decided that it would be best for both Sun Quan and Liu Bei to maintain friendly relations, so he invited Guan Yu to have negotations. During the talks, soldiers from both sides were stationed at least a hundred steps away from the meeting area, and those present at the meeting each carried only a sword.
Subsequently, Liu Bei received news that Cao Cao was planning to attack Hanzhong, which was seen as the northern gateway into Yi Province, so he quickly requested for a border treaty with Sun Quan. He asked Sun Quan to give him back Lingling and create a diversion for Cao Cao by attacking Cao's stronghold at Hefei; in return, Liu Bei ceded Changsha and Guiyang to Sun Quan, setting the new border along the Xiang River. Sun Quan agreed to the treaty terms.
Lu Su died of illness at the age of 45 in 217.
Lu Su's tomb is located on Mount Gui in present-day Hanyang District, Wuhan, Hubei. The hill was originally named Mount Dabie and later renamed to Mount Lu to commemorate Lu Su. It was renamed to Mount Gui during the Ming Dynasty and this name has been used until now. Lu Su's tomb was originally located on the southern end of the hill and was moved in 1955 to a park in the middle of the hill due to construction works.