一箭双雕 — “To achieve two goals with one action”

According to 'The History of the Northern Dynasties: Biography of Changsun Sheng', Changsun Sheng was a native of Luoyang during the Northern Zhou dynasty. He was exceptionally resourceful and skilled in martial arts, becoming a palace guard at the age of eighteen. It was Yang Jian, Duke of Sui, who truly recognized his talent. After a brief conversation, Yang Jian discerned his courage and wit, believing he would become a great general.

At that time, Shetu, the leader of the northern nomadic Tujue (Turkic) people, maintained friendly relations with Northern Zhou, exchanging envoys. To showcase their strength, both sides sent brave and intelligent individuals as envoys. However, the arrogant Shetu often looked down upon the envoys from Northern Zhou.

On one occasion, Changsun Sheng accompanied the chief envoy Yuwen Shenqing on a mission to the Tujue. Upon meeting Changsun Sheng, Shetu changed his usual disdainful attitude towards Northern Zhou envoys and requested Yuwen Shenqing to leave Changsun Sheng behind. Yuwen Shenqing agreed, and Changsun Sheng stayed with the Tujue. A whole year passed, and Shetu still kept Changsun Sheng by his side, not allowing him to return to Northern Zhou. Moreover, Shetu always insisted that Changsun Sheng accompany him on his hunts.

One day, Shetu saw two large eagles circling in the air, fighting over a piece of meat in front of his tent. Intrigued, he called Changsun Sheng, handed him two arrows, and ordered him to shoot down both eagles.

Changsun Sheng took the arrows, quickly mounted his horse, and galloped off. As he drew closer to the eagles, he nocked an arrow, aimed precisely, and fired. The single arrow pierced through the chests of both eagles, and they both fell to the ground simultaneously. Changsun Sheng's superb archery skills, shooting two eagles with one arrow, earned him cheers from the Tujue soldiers present. Shetu was also extremely pleased, ordering handsome rewards for Changsun Sheng and instructing his subordinates to learn archery from him.

Later, Yang Jian seized power from Northern Zhou and established the Sui Dynasty. The Tujue and other minority states took the opportunity to attack the Sui Dynasty, seeking revenge for Northern Zhou. By this time, Changsun Sheng had returned to the Sui Dynasty. He leveraged his intelligence, bravery, and knowledge of the Tujue's internal affairs to help Yang Jian repel their invasions multiple times.

This story later gave rise to the idiom "一箭双雕" (yī jiàn shuāng diāo) idiom, which is used to describe achieving two objectives with a single action.