In the spring and autumn period, Kingdom Jin wanted to expand their power, territory and destroy kingdom Guo. In order to do so, they came up with the excuse that Kingdom Guo always violated their border. 

The only problem now was that in order to get to Kingdom Guo they had to pass over Kingdom Yu. “How can we get to Kingdom Guo without putting danger onto ourselves?” Duke Xian the king of kingdom Jin asked his ministers. The minister Xun Xi replied: "the monarch of kingdom Yu is a greedy person with no vision, as long as we send him treasures and precious horses, we would be able to pass his country." Being able to tell that Duke Xian was reluctant to do, Xun Xi quickly added “Kingdom Yu and Kingdom Guo are interdependent neighbors; if Kingdom Guo is destroyed, Kingdom Yu will not be able to exist alone. Your treasures and horses are hence only temporarily stored in Kingdom Yu. " Duke Xian, having heard this, accepted Xun Xi’s suggestion and sent gifts to Kingdom Yu. 

     When the monarch of kingdoms Yu saw these precious gifts, he was delighted and agreed to allow Kingdom Jin’s troops to pass through their territory to get to Guo. Yu’s minster Gong Qi heard the message and hurried to stop it " No, no , kingdoms Yu and Guo are two small but interdependent countries. If Guo is destroyed, it will be difficult for us to survive too. The saying goes “ without lips, our teeth will also be lost,” we cannot let kingdom Jin’s troop pass through our country. " In response the king replied, " Jin is a big country and now they are befriending by giving us treasures and precious horses, why can’t we just let them pass through are Kingdom?” Gong Qi knowing that danger is not far from the kingdom, left the country with his whole family. 

When the day came, Kingdom Jin’s troops passed through Kingdom Yu and destroyed the Kingdom Guo , and as expected, they then captured the King of Kingdom Yu and swallowed up their Kingdom. Thus the saying “唇亡齒寒” is understood to mean the interdependent relationship between two groups of people.

by-Annie Tsao