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 unify¹ China. He called his civil and military officials to discuss the plan to destroy the Kingdom of Wu. Most of 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 powerfull. So it would be better to wait until fuller preparations were made.

三国末年，晋武帝司马炎灭掉蜀国，夺取魏国政权以后，准备出兵攻打东吴，实现统一全中国的愿望。他召集文武大臣们商量灭大计。多数人认为，吴国还有一定实力，一举消灭它恐怕不易，不如有了足够的准备再说。

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 decided² 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, mustered³ 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 grandeur⁴. 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 advantageous⁵ to withdraw the troops for the time being and wait until winter came. Du Yu resolutely⁶ opposed the idea, saying ," Now our army's morale⁷ is high,and our army is winning one victory after another, just like a sharp knife splitting a bamboo. It won't be too strenuous⁸ 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 unified⁹ the whole country. 大将杜预不同意多数人的看法，写了一道奏章给晋武帝。杜预认为，必须趁目前昊国衰弱，忙灭掉它，不然等它有了实力就很难打败它了。司马炎看了杜预的奏章，找自己的最信任的大臣张华征求意见。张华很同意杜预的分析，也劝司马炎快快攻打吴国，以免留下后患。于是司马炎就下了决心，任命杜预作征南大将军。 公元279年，晋武帝司马炎调动了二十多万兵马，分成六路水陆并进，攻打吴国，一路战鼓齐鸣，战旗飘扬，战士威武雄壮。第二年就攻占了江陵，斩了吴国一员大将，率领军队乘胜追击。在沅江、湘江以南的吴军听到风声吓破了胆，纷纷打开城门投降。司马炎下令让杜预从小路向吴国国都建业进发。此时，有人担心长江水势暴涨，不如暂收兵等到冬天进攻更有利。杜预坚决反对退兵，他说：“现在趁士气高涨，斗志正旺，取得一个又一个胜利，势如破竹（像用快刀劈竹子一样，劈过几节后竹子就迎刃破裂），一举攻击吴国不会再费多大力气了！” 晋朝大军在杜预率领下，直冲向吴都建业，不久就攻占建业灭了吴国。晋武帝统一了全国。

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 irresistible¹⁰ force or victorious¹¹ advance.

故事出自《晋书·杜预传》。成语“势如破竹”，形容战斗节节胜利，毫无阻挡。