Cao Pi ' s invasions of Eastern Wu During the Three Kingdoms period of Chinese history , Cao Pi , the first emperor of the state of Cao Wei , invaded the rival state of Eastern Wu thrice during his reign in 222 - 223 , 224 , and 225 . The " casus belli " for the attack was the Wu leader Sun Quan ' s refusal to send his son Sun Deng as a hostage to the Wei court , under which Wu was a nominal vassal at the time . The invasions were separated into two parts . The first attack occurred in the years 222 - 224 before Cao Pi ordered total retreat . The second and last part was fought in 225 . Background . After the Shu Han emperor Liu Bei was defeated by Sun Quan ' s forces at the Battle of Xiaoting , Sun benefited from his submission to Cao Pi , who would help him in the conflict against Liu Bei . However , on both sides , this was never a popular concept , especially in the ranks of Sun Quan , who defeated Cao Cao at the Battle of Red Cliffs 14 years ago . To make matters worse , Sun Quan and his officers were uneasy about Sun ' s titles and ranks ( such as King of Wu ) because it was quite inappropriate since they were seen as a vassal state under Wei . It was even considered within Sun Quan ' s forces that the alliance with Wei was futile , because the defeat they caused Liu Bei at Xiaoting was so critical that it meant that their alliance with Wei was no longer an asset for survival . Sun Quan also appeared as if he was planning to have this alliance go not much longer than it was supposed to . In a matter of time , Cao Pi ' s plan to keep Sun Quan and Shu ' s relations sour backfired as Sun Quan and Liu Bei rekindled their alliance . In an attempt to improve his own relations with the Sun clan , he demanded Sun Deng ( Sun Quan ' s eldest son ) to be sent to the Wei capital Luoyang as a hostage . However , Sun Quan declined this request , and later apologized to Cao Pi , stating his son was still very young and vulnerable in his health to be away from his home and family . Cao Pi did not bring up or press the matter . However Cao Pi demanded Sun Deng as hostage soon again . This was also declined . Diplomatic ties between the two continued to sour until finally , Cao Pi would attack Sun Quan . Sun Quan would repetitively send envoys to negotiate peace between the two , but resulted in failure . Soon after , Sun Quan would proceed into declaring independence in November 222 . First , second , and third invasions : ( 222 - 223 ) . Dongkou . In the autumn of 222 , Wei general Cao Xiu led a naval fleet down the Zijiang tributary river to the Yangtze onto the Wu stronghold at Dongkou , under the command of Wu general Lü Fan . The initial efforts of Wei were a success in battle against the Wu commander , but the Wu reinforcements led by Sun Shao and Xu Sheng managed to stalemate the naval attack . The battle concluded in late spring of 223 . Jiangling . Further west of the Yangtze , Wei generals Cao Zhen , Zhang He , and Xiahou Shang attacked two Wu positions in Jing Province from Xiangyang . Zhang He led the attack to overrun the outpost at Nan Commandery , successfully defeating Sun Sheng in the process . Cao Zhen and Xiahou Shang opened the siege of Jiangling , capital of Jing Province . Though , the Wu forces there were not strong and were under control of Zhu Ran . Though the siege was put on hold when Wu reinforcements led by Pan Zhang and Zhuge Jin arrived . Eventually the Wei camp was plagued by a disease , thus forcing another retreat and another stalemate . Ruxu . The third invasion was not directed into the region of Changsha nor Jing Province , but more closer to the Wu emperor Sun Quan instead . The late Wu general Gan Ning helped take the Wei outpost in Yang Province at Ruxu , on the eastern bay of present - day Lake Chao , therefore Cao Ren attacked Ruxu . Ironically , the assault also ended in retreat when Cao Ren learned that the other two armies attacking Dongkou and Jiangling withdrew from their positions . Rebellion of Jin Zong . In the summer of 223 , Wu general Jin Zong ( 晋宗 ) defected to Wei and moved to the new Wei outpost north of the Yangtze at Qichun . Wu general He Qi led the attack on Jin Zong , however , his forces decided to withdraw due to extremely hot weather conditions . He Qi managed to capture Jin Zong in the process . Fourth invasion : Incident at Guangling . The last invasion occurred in 225 , though no fighting officially occurred . Cao Pi led more than 100 , 000 in numbers made up of naval vessels towards the location at Guangling , on the opposite side of the Yangtze River from Jianye ( present - day Nanjing , Jiangsu ) . However , the Wu blockade was prepared and the winter was harsh ; thus Cao Pi had a slim chance of critical success if he was to engage in combat with Sun Quan . He sighed , and ordered the withdrawal of his forces .