There are many purposes of the Eastern Zhou vassal annexation war, but the essence is to compete for land and population.
Qi Jin s Empathy of "Creating a Great Power";
From the historical background, Pingdong moved eastward, especially after the war of Gege, the royal family declined and the government was ruled by Fang Bo, which provided conditions for the strength of Qi Jin.
In the early years of the Western Zhou Dynasty, vassals were enfeoffed. Qi and Jin Dun are important relatives of the royal family, with high status and strong military strength. The fief occupies an important geographical position and is a powerful material foundation of Qi and Jin Dynasties.
Qi Jin trained monarchs and scholars, such as Huan Gong and Guan Zhong of Qi, Jin's father-in-law and Wen Gong.
Carry out various reforms to enhance national strength, such as Guan Zhong reform in Qi State and Wen Gong reform in Jin State.