During the Spring and Autumn period （770－476BC）, the State of Wu launched an attack against the State of Yue. The King of Wu was seriously wounded and soon died. His son Fu Chai became the new King. Fu was determined to get revenge. He drilled his army rigidly until it was a perfect fighting force. Three years later, he led his army against the State of Yue and caught its king Gou Jian. Fu took him to the State of Wu.

In order to avenge his father's death, Fu let him live in a shabby stone house by his father's tomb and ordered him to raise horses for him. Gou pretended to be loyal to Fu but he never forgot his humiliation. Many years later, he was set free. Gou secretly accumulated a military force after he went back to his own state. In order to make himself tougher he slept on firewood and ate a gall-bladder before having dinner and going to bed every night. At the same time he administered his state carefully, developing agriculture and educating the people. After a few years, his country became strong. Then Gou seized a favorable opportunity to wipe out the State of Wu.

Later, people use it to describe one who endures self-imposed hardships to strengthen one's resolve to realize one's ambition.

    春秋時(shí)期，吳國(guó)和越國(guó)之間進(jìn)行了一場(chǎng)戰(zhàn)爭(zhēng)，吳王不幸受了重傷，不久就死了。他的兒子夫差作了吳國(guó)的新國(guó)王，他發(fā)誓要替父親報(bào)仇。于是，他嚴(yán)格的操練他的士兵，把他們訓(xùn)練成了一支非常厲害的軍隊(duì)。三年以后，他對(duì)越國(guó)發(fā)動(dòng)了戰(zhàn)爭(zhēng)，抓住了越王勾踐，把他帶回了吳國(guó)。

為了復(fù)仇，夫差讓勾踐住在他父親墓旁的破石屋里天天看墓、喂馬。勾踐表面上服從，心里面卻想著復(fù)仇。幾年以后，勾踐被放回越國(guó)。他立刻開(kāi)始秘密聚集一支軍隊(duì)。為了提醒自己不要忘了報(bào)仇，他睡在柴上，還每天在吃飯睡覺(jué)前嘗一嘗苦膽。同時(shí)，他專心治理國(guó)家，大力發(fā)展農(nóng)業(yè)，加強(qiáng)民眾教育。幾年后，越國(guó)又變得強(qiáng)大起來(lái)，然后，勾踐抓住一個(gè)適當(dāng)?shù)臋C(jī)會(huì)消滅了吳國(guó)。

后來(lái)，人們用它來(lái)形容人刻苦自勵(lì)以達(dá)到自己定下的目標(biāo)。