Yu Rang was a man from the state of Jin during the late Spring and Autumn period. He initially served under the Fan and Zhonghang clans, but was not valued by either. Later, he joined the service of Zhi Bo (also known as Zhi Yao), who greatly appreciated him and regarded him as a talented individual.
In 453 BC, Zhao Xiangzi, allied with the states of Han and Wei, destroyed Zhi Bo. Zhao Xiangzi harbored deep hatred for Zhi Bo, not only wiping out the entire Zhi clan but also using Zhi Bo’s head as a wine cup.
Yu Rang, upon learning this, was filled with grief and indignation. He fled to the mountains, declaring, “A man dies for one who understands him, a woman adorns herself for one who loves her,” and vowed to avenge Zhi Bo.
Yu Rang changed his name and disguised himself as a convict, infiltrating Zhao Xiangzi’s palace to clean the latrines, intending to assassinate him. Once, when Zhao Xiangzi went to the toilet, he suddenly felt uneasy and sensed something was wrong. He ordered a search, and sure enough, they captured Yu Rang, finding weapons among his tools. Moved by Yu Rang’s loyalty and righteousness, Zhao Xiangzi released him.
Yu Rang resolved to take revenge again. He covered his entire body in lacquer, causing his skin to fester like leprosy; he also swallowed charcoal to make his voice hoarse, completely altering his appearance and voice until even his wife couldn’t recognize him.
He ambushed Zhao Xiangzi under a bridge he was sure to cross (present-day Chiqiao Village, Taiyuan, Shanxi).
But as Zhao Xiangzi crossed the bridge, his horse suddenly became startled and refused to move. Zhao Xiangzi exclaimed, “This must be Yu Rang!” He ordered a search, and indeed, Yu Rang was captured again.
Zhao Xiangzi questioned Yu Rang: “You previously served the Fan and Zhonghang clans; why didn’t you avenge them when they were destroyed?” Yu Rang replied, “They treated me like an ordinary person, so I repaid them in an ordinary way; Zhi Bo treated me like a national hero, so naturally I must repay him in a national hero’s way!”
Knowing he was doomed, Yu Rang begged Zhao Xiangzi to take off his outer garment so he could stab it a few times, symbolically avenging Zhi Bo. Deeply moved by his loyalty, Zhao Xiangzi took off his garment and handed it to him. Yu Rang drew his sword, leaped up, and stabbed the garment three times, shouting, “Now I can repay Zhi Bo!” Then he drew his sword and committed suicide.
豫让是春秋末期晋国人。他先在范氏、中行氏手下做事，但都不受重视。后来他投靠智伯（也叫智瑶），智伯非常器重他，把他当人才看待。
公元前453年，赵襄子联合韩、魏两家灭掉了智伯。赵襄子特别痛恨智伯，不仅灭了智氏全族，还把智伯的头颅做成酒杯来喝酒。
豫让知道后非常悲愤，逃到山中说：”士为知己者死，女为悦己者容”（好男儿要为赏识自己的人牺牲，女子要为喜欢自己的人打扮），我一定要为智伯报仇。
豫让改名换姓，伪装成受过刑的犯人，混进赵襄子的宫中打扫厕所，想趁机刺杀。有一次赵襄子上厕所时，突然心里发慌，觉得不对劲，就命人搜查，果然抓到了豫让，还在他工具上发现了武器。 赵襄子被豫让的忠义感动，竟然放了他。
豫让决心再次报仇。他用漆涂满全身，使皮肤溃烂像长了癞疮；又吞下火炭，把嗓子弄哑，彻底改变容貌和声音，连他妻子都认不出他了。他埋伏在赵襄子必经的一座桥下（今山西太原赤桥村），但赵襄子过桥时，马突然受惊不肯前行。赵襄子说：”这一定是豫让！”派人搜查，果然又抓到了他。
赵襄子责问豫让：”你以前也侍奉过范氏、中行氏，他们被灭时你为什么不报仇？”豫让回答：”他们待我如普通人，我便以普通人的方式回报；智伯待我如国士，我自然要以国士的方式报答他！”
豫让知道自己必死，请求赵襄子把外衣脱下来给他，让他刺几剑，象征性地为智伯报仇。赵襄子被他的忠义深深感动，脱下衣服递给他。豫让拔剑跳起来，对着衣服连刺三下，高喊：”我可以报答智伯了！”然后拔剑自刎而死。
– 出自《史记·刺客列传》From Records of the Grand Historian: Biographies of Assassins