In the final years of the Qin Dynasty, after Chen Sheng and Wu Guang raised the first rebellion, Xiang Liang and his nephew Xiang Yu also rose up in Wuzhong. To unite more anti-Qin forces, Xiang Liang installed Xiong Xin, grandson of King Huai of Chu, as the new King Huai of Chu.
When the Second Emperor of Qin saw the realm descending into chaos, he dispatched the great general Zhang Han to lead the imperial army in suppressing the peasant uprisings. Soon, Chen Sheng and Wu Guang were defeated and killed by Zhang Han, and Xiang Liang also fell in battle against the Qin forces. Flush with victory, Zhang Han turned his attention to attacking the state of Zhao. The Zhao army retreated to the city of Julu, where they were completely surrounded by Zhang Han's troops.
When the Zhao army sent an urgent plea for aid, King Huai of Chu appointed the strategist Song Yi as supreme general, with Xiang Yu as his deputy, to lead a relief force to save Zhao.
When General Song Yi led his army to Anyang, he lingered there for over forty days without advancing. Xiang Yu urged him forward, saying, "We must march quickly to Julu and join forces with the Zhao army from within and without to crush the Qin forces."
Song Yi shook his head and refused, saying, "Now the Qin army is attacking Zhao. Even if they win, their forces will be greatly depleted. We can then take advantage of their exhaustion and defeat them. If the Qin army loses, we can march west and capture Qin itself. When it comes to wearing armor and wielding weapons in battle, I, Song Yi, am not your equal. But when it comes to sitting in the tent and devising strategies, you are far inferior to me."
Song Yi then issued another order: anyone who disobeyed his command would be beheaded.
Xiang Yu knew that Song Yi's order was directed at him, and he burned with fury. The weather was bitterly cold, and the soldiers shivered and starved in their camp, yet Song Yi feasted and drank every day. Unable to endure it any longer, Xiang Yu killed Song Yi in a rage and proclaimed to the entire army, "Song Yi plotted rebellion, and I have executed him on the secret orders of the King of Chu. Now we march immediately to rescue Zhao!"
The assembled officers immediately rallied behind Xiang Yu, appointing him acting supreme general, and sent word to King Huai, who formally confirmed the appointment. Donning armor and taking up arms, Xiang Yu led his troops to Julu, charging ahead of his men in a fierce assault on the Qin forces, ultimately crushing them in a decisive victory.
From that point on, Xiang Yu's reputation spread far and wide, and he became the most renowned leader of the peasant rebel armies of his time.
Later, the idiom "Donning Armor and Wielding Weapons" came to describe wearing strong armor and holding weapons while engaging in battle.
Source: *Records of the Grand Historian*, "Biography of Xiang Yu"
Meaning of the Idiom: Later, the Chinese idiom "披坚执锐" came to describe wearing strong armor and holding weapons while engaging in battle.