During the Northern Qi dynasty, a pivotal figure named Gao Dezheng rose to prominence. Clever and handsome from youth, he caught the eye of Prime Minister Xianzu (Gao Yang, son of the founder), who appointed him as a key advisor. Their bond was so strong that Gao Dezheng spoke his mind without reservation, and Xianzu followed every suggestion. Soon, Xianzu promoted Gao Dezheng to imperial attendant, making him a trusted confidant.
In the fifth year of Wuding (543 AD), the founding emperor passed away in Jinyang. The Grand General and Prince of Bohai, Shizong (the emperor's eldest son), inherited his father's legacy and traveled to Jinyang to handle the funeral. Xianzu remained in Ye (the capital) and appointed Gao Dezheng to assist in managing the state's military and political affairs, their bond growing increasingly close.
Emperor Shizong was killed by bandits in Jinyang, a sudden event that shocked the court. Gao Dezheng urged Emperor Xianzu to take the throne, arguing, "A kingdom cannot be without a ruler for even a single day." But the ministers were divided, and even the Empress Dowager issued an edict: "Your father was a dragon, your elder brother a tiger, yet they only served as ministers. How can you surpass them and become emperor? This is surely not your own idea—Gao Dezheng has put you up to this."
Of course, Gao Dezheng's words struck a chord with Emperor Wenxuan. In 550 AD, he finally ascended the throne, becoming Emperor Wenxuan of Northern Qi. On the day of his abdication, he appointed Gao Dezheng as an imperial advisor, later promoting him to Minister of the Right and concurrently imperial advisor, a position equivalent to prime minister.
Six or seven years later, Emperor Wenxuan, swollen with pride over his achievements, sank into a life of wine and women. Gao Dezheng repeatedly submitted blunt memorials to the emperor's face, which earned him the ruler's deep displeasure, and in the end, Emperor Wenxuan had him executed.
Later, the idiom "speaking without reservation" came to describe expressing one's thoughts completely.
Source: *Book of Northern Qi*, "Biography of Gao Dezheng"
Meaning of the Idiom: Later, the Chinese idiom "言无不尽" came to describe expressing one's thoughts completely.