Aggressive civil and military reforms
Despite being over 60 years of age when he became the ruler of Jin, Chonger energetically plunged into the reform of the state’s civils and military institutions. His introduction of the so-called three-army system played an important part in boosting the strength of Jin by enabling the military to operate with much greater flexibility.
A rising power
As his power and prestige grew, Chonger greatly increased the size of Jin by absorbing many of the smaller states surrounding it and turning others into vassals. When King Xiang of Zhou was deposed by his brother in 635 BCE, he took the opportunity to further increase the influence and power of Jin by forging a coalition of states to restore him to his throne.
Some critics accuse Chonger of becoming so arrogant that he broke the rules of propriety by summoning King Xiang to his court under the pretext of inviting him to a hunt to show his nominal superior that he was in charge. This is why Confucius criticizes him as “crafty and improper” in Analects 14.15.
A stunning triumph
Despite or perhaps because of his disregard for ritual propriety, Chonger provided further evidence of the greatness of his statecraft when he assembled another grand coalition, including troops from Qin, Qi, and Song, to defend Song against invasion from Chu in the south.
The stunning triumph he achieved over Chu forces at the Battle of Chengpu in 632 BCE not only put a stop to the plans of this rich and powerful southern state to take over the north; it also meant that he was confirmed as hegemon at the Jiantu conference in 631 BCE.
A strong foundation
Chonger died three years later in 628 BCE, having transformed Jin into a major player on the Zhou dynasty stage in the space of just eight years. The reforms he implemented provided a strong foundation for his successors to further expand the power and influence of Jin over the next few decades, only for the ruling family to fall prey to vicious infighting over power like so many of its counterparts in other states during the Spring and Autumn period.