成汤是契的后代，也是商朝的开国君主。
有一天，他在野外出游时，看到了一个猎人正在四面张网设置陷阱。
猎人高兴地说：“无论是从天上飞来，从地下、地上钻出跑来的，或从四方而来的各种鸟兽，都会进入我的网内。”
成汤听了后说：“唉！你这么做是赶尽杀绝，和残暴的夏桀有什么不同呢？”
于是，成汤便撤除了三面网子，只留置一面网子让猎人捕捉猎物。
后来，四方诸侯都听到了这件事，同声说：“成汤真是有仁德，就连禽兽都受到他的恩泽了。”
因此而来归顺的诸侯，高达四十余国。
不久，夏桀因施行暴政，致生灵涂炭，于是成汤便出兵征伐，夏亡。
成汤将夏桀放逐于南巢，在亳即位，国号为商。
“一网打尽”这句成语就是从这个故事浓缩而来，原指用网子把鸟兽、鱼全部抓住，后来被引申用来比喻排除异己，无一遗漏。
Cheng Tang was the descendant of Qi and the founding monarch of the Shang Dynasty.
One day, while out hunting in the wild, he saw a hunter setting traps with nets on all sides.
The hunter happily said, "Whether flying from the sky, crawling from underground, running from the ground, or coming from all directions, all kinds of birds and beasts will enter my net."
After hearing this, Cheng Tang said, "Alas! What you are doing is driving them to extinction. How is it different from the cruel rule of King Jie of the Xia Dynasty?"
So Cheng Tang removed three sides of the nets and left only one side for the hunter to catch prey.
Later, the princes from all four directions heard about this and said in unison, "Cheng Tang is truly benevolent. Even the animals have received his grace."
As a result, more than forty states came to swear allegiance to him.
Soon after, due to his tyrannical rule, King Jie of the Xia Dynasty brought disaster upon the people, so Cheng Tang led an army to overthrow him. The Xia Dynasty fell.
Cheng Tang exiled King Jie to Nanchao and ascended the throne in Bo. He named his state the Shang Dynasty.
The idiom 'One Net to Catch Them All' comes from this story. It originally referred to using a net to catch all birds and fish, but later it was extended to mean eliminating all dissenters without exception.
