in the last years of the three kingdoms period,sima yan conquered the kingdom of shu and seized the state power of the kingdom of wei, and became emperor wudi of the jin dynasty. then he planned to send his troops to attack the kingdom of wu so as to unify china. he called his civil and military officials to discuss the plan to destroy the kingdom of wu. most of the them thought that it would be difficult to try to destroy the kingdom of wu with one action because the kingdom of wu was still powerfou. so it would be better to wait until fuller preparations were made. however,general du yu did not agree with them, so he wrote a memorial to the throne. according to du yu, it would be better to destroy the kingdom of wu as soon as possible, because it was still weak at that time. it would be more difficult to defeat the kingdom of wu later if it became stronger. after reading it, emperor wudi to send troops to attack the kingdom of wu as early as possible, so as to avoid future trouble. so emperor wudi made up his mind, and appointed du yu the grand general for conquering the south . in 279, sima yan, emperor wudi of the jin dynasty, mustered more than two hundred thousand troops who were divided into six army divisions to proceed by both land and water to attack the kingdom of wu. battle drums thundering and the colours fluttering, the soldiers were full of power and grandeur. the next day, jiangling city was captured, and a general of the kingdom of wu was killed. and the jin army pushed on in the flush of victory. hearing this, the troops of the kingdom of wu south of the yuanjiang river and the xiangjiang river were overwhelmed with fear, and they opened the gates of cities and surrendered one after another. sima yan ordered du yu to advance to jianye, capital city of the kingdom of wu, by water.someone feared that the yangtze river might have a sharp rise and thought it more advantageous to withdraw the troops for the time being and wait until winter came. du yu resolutely opposed the idea, saying ," now our army's morale is high,and our army is winning one victory after another, just like a sharp knife splitting a bamboo. it won't be too strenuous to conquer the kingdom of wu with one action. " under du yu's command , the jin army charged at the capital city jianye, occupied it ,and thus destroyed the kingdom of wu. in this way, emperor wudi of the jin dynasty unified the whole country. this story appears in "the life of du yu "in the history of the jin dynasty. later the set phrase" like splitting a bamboo" is used to refer to irresistible force or victorious advance.