"I recall that Dawei adopted the Nine-Rank System because we were in the midst of the post-founding chaos. Not long after the Three-Way Partition of Jin, the Emperor Yongde feared the influence of the aristocratic clans and proposed the Nine-Rank System to select talent, hoping to win their allegiance."
Regarding the Three-Way Partition of Jin, Jia Lingyun had already learned the full history from Jia Yi. Originally, the three states of Wei, Shu, and Wu had all belonged to the Jin State. At that time, three powerful scholar-officials held total sway over the imperial court. With the help of some mysterious power, the three swore an oath, declared themselves emperors, partitioned the territory, and established the states of Wei, Shu, and Wu, carving up the former Jin State entirely.
The Nine-Rank System was an inevitable product of that era; without the support of the aristocrats, their thrones would never have been secure.
Chapter 19