The Qin Empire, Volume Two: The Nation's Destiny and the Art of Power, Part Two

The six states formed an alliance to resist Qin. Qin appointed Zhang Yi as its chancellor, using diplomacy to break the alliance and pursuing further growth as the powerful state rose to prominence.

King Hui of Qin allied himself with the reformers, ruthlessly suppressing rebellions by the old aristocracy and restoring order at court. He appointed young pillars of talent loyal to the new laws, forming a vigorous new generation at the heart of power and making full preparations to advance east into the Central Plains. At the time, the six states east of the mountains were mired in chaos and conflict. Taking advantage of this, Qin's new army advanced east and won a string of great victories, posing a grave threat to the six states.

Two renowned men from the school of Guiguzi entered the world: Su Qin and Zhang Yi, fellow disciples, surveyed the realm and agreed to each serve a great state. Both suffered major setbacks and were forced to withdraw for a time. Su Qin endured humiliation and studied hard for three years. Having grasped the wider situation, he returned to public life and proposed a grand strategy of uniting the states against Qin. Starting in Yan, he successfully persuaded the six states to form an alliance. As chancellor of all six states, he joined forces with the Four Great Young Lords of the Warring States to assemble a coalition army that put Qin under immense pressure. Qin resolved to resist the six states and sought out Zhang Yi, who was already confident he could break their alliance, appointing him chancellor. Zhang Yi proposed a grand strategy of allying with distant states to attack nearby ones, and oversaw Qin's diplomatic maneuvering and all-out struggle for power against the six states east of the mountains. The coalition army invaded Qin, but its weak foundations and frequent internal conflicts led to repeated defeats, and the alliance collapsed. Su Qin was murdered by assassins hired by the old aristocracy.

At this point, Qin's domestic politics shifted. King Hui developed a strange illness with no clear cause, while the violent crown prince and Chief Historian Gan Mao conspired to drive out their rivals. General Sima Cuo was forced to resign and retire, while Zhang Yi, fearing dismissal, resigned and left Qin to live in seclusion in the countryside. The warlike King Wu of Qin led a great army east to Luoyang, once again pushing Qin into a dangerous position.