Zheng was extremely reluctant to give away that piece of land, and indeed his courtiers begged him to reject the proposal, but out of courtesy for his mother he agreed.
Seeing that her plan was going well, Zheng's mother urged Duan to build walls, stockpile arms and recruit mercenaries to the rebel cause.
However, Zheng dismissed these proposals, stating that he found no fault in Gongshu Duan, and besides, it could not be proved that he was plotting a coup, instead of just merely reinforcing the border.
Soon King Zheng had left the dukedom to Luoyang for some diplomatic matters; his mother soon wrote a letter to Duan, ordering him to revolt now and she would open the gates of the capital for him.
Duke Zhuang defeated Gongshu Duan at Yan (north of present-day Yanling County) during the summer in the fifth month of 722 BC.
But when public opinion began to turn against him as a result of this, he soon dug a tunnel linking his and his mother's palaces, and there they met, burying the hatchet altogether.
[citation needed] No more than 1 year later, Duke Xiang of Qi, who wanted fame, pretended to invite Men and Gao Qumi to Shouzhi and had them killed.
[citation needed] 17 years later, Duke Li with Qi troops defeated Yi, killed his two sons and managed to restore himself to power (in 680 BCE[8]).