Since Shang Yang's political reform, Qin became the first of the Seven Heroes in the Warring States with its strong national strength. The six countries east of Tongguan were at a loss in the face of the aggressive situation of Qin State. Su Qin, a native of Luoyang, put forward the strategy of combining vertical forces to resist Qin. The basic point of vertical integration strategy is the geographical advantage formed by the joint efforts of the six countries. In 333 BC, Su Qin lobbied successfully, and the envoys of the six countries joined forces in Huanshui (now Anyang, Henan) to form an anti-Qin alliance. Su Qin is the Chief Executive. The six countries agreed on a joint action plan to deal with Qin. The six countries with geographically connected and related interests have survived in front of Qiang Qin for one hundred years, relying on the joint strength.
The geographical relationship between the six countries and Qin is different, and their enthusiasm for the alliance is also different. Zhang Yi believes that the six-nation alliance can be disintegrated by Lian Heng's strategy of making diplomatic contacts with Tomochika. Zhang Yi's proposition was supported by King Qin Huiwen. Zhang Yi and Su Qin are both students of the military strategist Guiguzi, who are proficient in the art of vertical and horizontal coitus. Zhang Yi worked for Lian Heng and lobbied for the disintegration of the alliance.