Guo Huai (died 23 February 255), courtesy name Boji, was a Chinese military general of the state of Cao Wei during the Three Kingdoms period of China. He started his career towards the end of the Eastern Han dynasty under the warlord Cao Cao as a subordinate of Cao Cao's generals Xiahou Yuan and Zhang He. During the Three Kingdoms period, he served in Wei, the state established by Cao Cao's son Cao Pi, and lived through the reigns of four Wei emperors (Cao Pi, Cao Rui, Cao Fang and Cao Mao). From the 220s until his death in 255, he governed and defended Wei's western borders in Yong and Liang provinces (covering parts of present-day Gansu, Shaanxi, Ningxia, Qinghai and Inner Mongolia). During this time, he resisted multiple invasions by Wei's rival state, Shu Han, and quelled some rebellions by local Qiang, Di and other non-Han Chinese tribes.
Family background Guo Huai was from Yangqu County (), Taiyuan Commandery, which is located southwest of present-day Yangqu County, Shanxi.(郭淮字伯濟，太原陽曲人也。) Sanguozhi vol. 26. His grandfather Guo Quan () and father Guo Yun () served as the Grand Minister of Agriculture () and Administrator () of Yanmen Commandery (near present-day Xinzhou, Shanxi) respectively in the Eastern Han dynasty.(案郭氏譜：淮祖全，大司農；父縕，鴈門太守。) Guo Shipu annotation in Sanguozhi vol. 26.
Guo Huai started his career in the middle of the Jian'an era (196–220) of Emperor Xian's reign in the late Eastern Han dynasty. He was nominated as a xiaolian (civil service candidate) and was subsequently appointed as an assistant official in Pingyuan Commandery.(建安中舉孝廉，除平原府丞。) Sanguozhi vol. 26.
Service under Cao Cao
When Cao Pi held the position of General of the Household for All Purposes () between 211 and 220, he recruited Guo Huai to serve as an officer in the law enforcement bureau under his charge. Guo Huai was later reassigned to be a clerk in the military affairs bureau of the office of the Imperial Chancellor,(文帝為五官將，召淮署為門下賊曹，轉為丞相兵曹議令史， ...) Sanguozhi vol. 26. the position held by Cao Pi's father Cao Cao, the warlord who controlled the Han central government and the figurehead Emperor Xian since 196.Zizhi Tongjian vol. 62.
In 215,Zizhi Tongjian vol. 67. Guo Huai accompanied Cao Cao on a campaign against a rival warlord, Zhang Lu, in Hanzhong Commandery. After defeating Zhang Lu and capturing Hanzhong Commandery, Cao Cao left his general Xiahou Yuan behind to guard Hanzhong against possible attacks by another rival warlord, Liu Bei, who was in the nearby Yi Province (covering present-day Sichuan and Chongqing). Guo Huai also remained in Hanzhong and served as a Major () under Xiahou Yuan's command.(... 從征漢中。太祖還，留征西將軍夏侯淵拒劉備，以淮為淵司馬。) Sanguozhi vol. 26.
In 217,Zizhi Tongjian vol. 68. Liu Bei launched a campaign to seize control of Hanzhong Commandery from Cao Cao's forces. Guo Huai did not participate in the initial battles as he was ill. After Xiahou Yuan was killed in action at the Battle of Mount Dingjun in 219, there was much panic and fear among Cao Cao's forces in Hanzhong as they had lost their commander. Guo Huai managed to restore order and stability within Cao Cao’s forces in two ways: First, he gathered and regrouped the soldiers who scattered when Xiahou Yuan was killed. Second, he nominated Zhang He to replace Xiahou Yuan as the commander of Cao Cao's forces in Hanzhong.(淵與備戰，淮時有疾不出。淵遇害，軍中擾擾，淮收散卒，推盪寇將軍張郃為軍主，諸營乃定。) Sanguozhi vol. 26.
The following day, when Cao Cao's forces received news that Liu Bei's forces were preparing to cross the Han River to attack them, most of Cao Cao's officers suggested that they should make camp on the riverbank and take advantage of the river as a natural barrier to resist the enemy, who had superiority in numbers.(其明日，備欲渡漢水來攻。諸將議衆寡不敵，備便乘勝，欲依水為陣以拒之。) Sanguozhi vol. 26. Guo Huai disagreed and said: "This isn't the best move because it reveals our weakness to the enemy and can't deter them. Why don't we make camp further away from the river, lure the enemy to attack our camp, and strike back when they are halfway across? We can defeat Liu Bei if we do this."(淮曰：「此示弱而不足挫敵，非筭也。不如遠水為陣，引而致之，半濟而後擊，備可破也。」) Sanguozhi vol. 26. Zhang He and the other officers followed Guo Huai's plan. When Liu Bei saw that the enemy camp was further away from the river, he became suspicious and did not send his troops across the river to attack. Guo Huai also ordered his troops to strengthen their defences and show Liu Bei's forces that they were prepared to hold their ground.(旣陣，備疑不渡，淮遂堅守，示無還心。) Sanguozhi vol. 26. Cao Cao was very pleased when he heard about what Guo Huai did. He also approved Zhang He's command and ordered Guo Huai to continue serving as a Major under Zhang He.(以狀聞，太祖善之，假郃節，復以淮為司馬。) Sanguozhi vol. 26.
Service under Cao Pi Following Cao Cao's death in March 220, his son Cao Pi succeeded him as the Imperial Chancellor and vassal King of Wei () under the Eastern Han dynasty.Zizhi Tongjian vol. 69. Cao Pi awarded Guo Huai the title of a Secondary Marquis () and reassigned him to be the Chief Clerk () under the General Who Guards the West ().(文帝即王位，賜爵關內侯，轉為鎮西長史。) Sanguozhi vol. 26.
Later that year, Cao Pi appointed Guo Huai as acting Army Protector Who Attacks the Qiang () and ordered him to join Zhang He and Yang Qiu in leading imperial forces to attack Zheng Gan's () bandit forces and the Lushui barbarians () in the Guanzhong region. They succeeded in their mission and restored peace and stability in the Guanzhong region.(又行征羌護軍，護左將軍張郃、冠軍將軍楊秋討山賊鄭甘、盧水叛胡，皆破平之。關中始定，民得安業。) Sanguozhi vol. 26.
In late 220, Cao Pi usurped the throne from Emperor Xian, ended the Eastern Han dynasty, and established the Cao Wei (or Wei) state with himself as the new emperor. As Guo Huai fell sick on his journey to the imperial capital Luoyang and had to rest until he was well, he showed up late to congratulate Cao Pi on his coronation.(黃初元年，奉使賀文帝踐阼，而道路得疾，故計遠近為稽留。) Sanguozhi vol. 26. Later, while hosting a banquet to celebrate his coronation, Cao Pi sternly asked Guo Huai in front of all the guests: "In the past, when Yu the Great called the nobles to attend an assembly at Tushan, Fangfeng showed up late and was executed as punishment. Today, you showed up late for the festivities. Why is that so?"(及群臣歡會，帝正色責之曰：「昔禹會諸侯於塗山，防風後至，便行大戮。今溥天同慶而卿最留遲，何也？」) Sanguozhi vol. 26. Guo Huai replied: "I heard that the Five Emperors taught and ruled their people by virtue. The use of punishments started in the Xia dynasty when its rule began to weaken. Today, as I am living in an age comparable to that of Yao and Shun's time, I know that I won't face the same fate as Fangfeng."(淮對曰：「臣聞五帝先教導民以德，夏后政衰，始用刑辟。今臣遭唐虞之世，是以自知免於防風之誅也。」) Sanguozhi vol. 26.
Cao Pi was so pleased to hear Guo Huai's response that he appointed him as the acting Inspector () of Yong Province and enfeoffed him as the Marquis of Sheyang Village (). Guo Huai was officially commissioned as the Inspector of Yong Province about five years later.(帝恱之，擢領雍州刺史，封射陽亭侯，五年為真。) Sanguozhi vol. 26. Sometime between 220 and 226, Guo Huai led Wei forces to suppress a rebellion by the Qiang chieftain Biti () in Anding Commandery (安定郡; around present-day Zhenyuan County, Gansu). Whenever the Qiang and other tribal leaders in Yong Province expressed their willingness to submit to Wei rule, Guo Huai always sent his subordinates to gather information about their clans (e.g. demographics) first. When he spoke to the leaders, he surprised and impressed them with his knowledge about their clans. He also paid close attention to, and showed understanding towards the concerns they had. The people in Yong Province praised him as a brilliant and wise governor.(安定羗大帥辟蹏反，討破降之。每羌、胡來降，淮輙先使人推問其親理，男女多少，年歲長幼；及見，一二知其款曲，訊問周至，咸稱神明。) Sanguozhi vol. 26.
Service under Cao Rui In 228, Wei's rival state Shu Han (or Shu) launched the first of a series of invasions on Wei territories in Yong Province. Zhuge Liang, the Imperial Chancellor of Shu, led the campaign and deployed his troops at Mount Qi (祁山; the mountainous areas around present-day Li County, Gansu). He then sent Ma Su to lead the Shu vanguard to attack Jieting (街亭; in present-day Qin'an County, Gansu) and Gao Xiang to lead another force to station at Liucheng (柳城; in present-day Zhangjiachuan, Gansu) as backup for Ma Su.(太和二年，蜀相諸葛亮出祁山，遣將軍馬謖至街亭，高詳屯列柳城。) Sanguozhi vol. 26. In response to this invasion, Zhang He led an army to attack Ma Su at the Battle of Jieting and inflicted a devastating defeat on the enemy. At the same time, Guo Huai also led a force to attack Gao Xiang's camp at Liucheng and succeeded in destroying it. Guo Huai then followed up by attacking Tangti (), a rebellious Qiang tribal chief from Longxi Commandery (around present-day Longxi County, Gansu), and defeated him at Fuhan County (枹罕縣; southwest of present-day Linxia County, Gansu). The Wei government granted him the additional appointment of General Who Establishes Might () to honour him for his achievements.(張郃擊謖，淮攻詳營，皆破之。又破隴西名羌唐蹏於枹罕，加建威將軍。) Sanguozhi vol. 26.
Battle of Jianwei
In the spring of 229, when Shu forces led by Chen Shi attacked Wudu (武都; around present-day Cheng County, Gansu) and Yinping (陰平; present-day Wen County, Gansu) commanderies, Guo Huai led Wei forces to resist them. However, he retreated after Zhuge Liang led a Shu army to Jianwei (建威; in present-day Longnan, Gansu) as backup for Chen Shi. The Shu forces then conquered Wudu and Yinping commanderies.([建興]七年，亮遣陳戒攻武都、陰平。魏雍州刺史郭淮率衆欲擊戒，亮自出至建威，淮退還，遂平二郡。) Sanguozhi vol. 35.Zizhi Tongjian vol. 71.
Battle of Mount Qi
In 231, during the Battle of Mount Qi between Wei and Shu, when the Wei army ran short of food supplies, the Wei government considered transporting food supplies from the Guanzhong region to the frontline at Longxi Commandery because the granaries in Longxi were empty.(五年，蜀出鹵城。是時，隴右無穀，議欲關中大運， ...) Sanguozhi vol. 26. Guo Huai turned to the local Qiang and Di tribes for aid and managed to convince them to donate food supplies to the Wei army. He then allocated them accordingly such that all units had sufficient food supplies. The Wei government reassigned him from his position as General Who Establishes Might () to General Who Spreads Martial Might ().(... 淮以威恩撫循羌、胡，家使出穀，平其輸調，軍食用足，轉揚武將軍。) Sanguozhi vol. 26.
Battle of Wuzhang Plains
In 234, Guo Huai joined Sima Yi in leading Wei forces to resist another Shu invasion led by Zhuge Liang. When Sima Yi and his troops were stationed at the south of the Wei River, Guo Huai urged them to move to the plains on the north bank of the river as he foresaw that Zhuge Liang would attempt to seize the plains. When the other officers disagreed,(青龍二年，諸葛亮出斜谷，並田于蘭坑。是時司馬宣王屯渭南；淮策亮必爭北原，宜先據之，議者多謂不然。) Sanguozhi vol. 26. Guo Huai said, "If Zhuge Liang crosses the Wei River and occupies those plains, his troops will have access to the mountains in the north. If they block the road through the mountains, it will cause fear and panic among the people living in the region. This isn't helpful to our State."(淮曰：「若亮跨渭登原，連兵北山，隔絕隴道，搖盪民、夷，此非國之利也。」) Sanguozhi vol. 26. Sima Yi agreed with Guo Huai and sent him to occupy the plains. While Guo Huai and his men were building a camp on the plains, they came under attack by Shu forces but managed to drive them back.(宣王善之，淮遂屯北原。塹壘未成，蜀兵大至，淮逆擊之。) Sanguozhi vol. 26.
Several days later, when Guo Huai received news that Zhuge Liang was planning to launch an attack in the west, his subordinates wanted to strengthen the defences in the west. Guo Huai was the only one who recognised that it was a ruse, and that Zhuge Liang was actually planning to attack Yangsui (陽遂; the area north of the Wei River in present-day Mei and Fufeng counties, Shaanxi). He was proven right later as the Shu forces attacked Yangsui at night. However, as Guo Huai had set up defences earlier, the Shu forces failed to capture Yangsui.(後數日，亮盛兵西行，諸將皆謂欲攻西圍，淮獨以為此見形於西，欲使官兵重應之，必攻陽遂耳。其夜果攻陽遂，有備不得上。) Sanguozhi vol. 26.
Service under Cao Fang