What kind of diplomacy did the state of Qin actually use, the alliance political strategy?

One of Qin's diplomatic tactics was the political strategy of marriage. In the early days, the state of Qin was not very powerful, so in order to stabilize its power and to seek foreign aid, it resorted to marriages with other countries. During the entire history of Qin, there were more than 10 marriages of vassals. The most famous one was during the period of Duke Xiang of Qin, who married his sister Mu Win to the King of Feng of Xijong, which brought the relationship between the two countries to a new level. The Duke of Qin stabilized the rear of the state through the marriage and laid the foundation for the subsequent rise of the state of Qin.

There were many reasons behind the chaotic wars throughout the Spring and Autumn and Warring States Periods, with some kings even using their own children and siblings as bargaining chips in political negotiations. For example, the ruler of the state of Qin often used marriage politics as a tactic. During the time of Duke Mu of Qin, he married his daughter Liang to the king of Jin, who later gave birth to the crown prince, Duke Huai of Jin, and since then the path of friendship between Qin and Jin began. Even with such a close relationship, Qin married Huai Ying to Duke Huai of Jin, and the relationship between the two countries reached its peak once again.

The political marriage of Qin did bring a great deal of peace and stability to the state. Many of Qin's rulers have utilized this political alliance to its fullest extent, and it has to be admitted that Qin's eventual rise to power is inextricably linked to this political alliance.

The first person to adopt this political marriage was the Duke of Qin Mu, who initiated this political marriage. While Qin was in favor with Jin, he married Qin's children to the king of Chu, King Cheng of Chu, so that Qin had the protection of Jin in the north and the blessing of Chu in the south.

The politics of marriage in ancient times brought great benefits to both countries and their people, but the daughter or sister of the king in the marriage could lose their lifelong happiness.