During the Eastern Jin Dynasty, the Grand Marshal Huan Wen had a military advisor named Xi Chao, who was exceptionally strategic. When discussing state affairs, he always offered penetrating and original insights, earning Huan Wen's high regard and becoming his top strategist.
Huan Wen, son-in-law of Emperor Yuan of Jin, was a man of exceptional talent and high status. Holding key military posts, he commanded powerful armies and guarded the strategic gates of Jingzhou and Yangzhou. Later, as Grand General of the Western Expedition, he recaptured vast territories lost to the Xiongnu for decades, including the former capital Luoyang, earning great merit and immense prestige.
However, Huan Wen's immense power and his growing ambition to replace the emperor aroused suspicion and jealousy from the throne and many ministers. They set up obstacles everywhere to prevent Huan Wen from gaining further influence.
During the Eastern Jin Dynasty, the northern border was frequently threatened by the Later Zhao state led by the Jie chieftain Shi Hu. The general Huan Wen repeatedly petitioned the court to launch a campaign against Later Zhao, but each time his requests were denied. Instead, the court dispatched incompetent generals to confront the enemy.
Huan Wen understood the situation all too well—frustrated yet without a good plan, he often secretly discussed with Xi Chao, plotting how to remove the obstacles to his usurpation of power.
One evening, Xi Chao was summoned to Huan Wen's residence. Huan Wen said to him, "Those who have repeatedly opposed me—I truly wish to kill them all for satisfaction." Xi Chao advised, "Seeking only satisfaction without considering the consequences may make matters even more difficult."
He believed that winning over the highly respected figures at court was essential.
"Take, for example, Minister of Personnel Xie An and Imperial Advisor Wang Tanzhi—we should do our utmost to win them over."
That night, they deliberated until midnight, drawing up a list of those to be killed, before the two of them lay down to sleep on the same bed.
The next morning, Huan Wen invited Xie An and Wang Tanzhi to his residence, but had Xi Chao hide behind a curtain to eavesdrop. Xie An and Wang Tanzhi asked, "The Grand Marshal summons us—what urgent matter is there?" Huan Wen replied, "I ask you two to advise me." He then took out a list and handed it to them.
Xie An, ever composed, took the list and read it, his heart racing but his face betraying nothing as he pondered a response. Wang Tanzhi, after reading it, noted several names of the emperor's most trusted ministers and thought, "You can't just kill them on a whim." He pointed at a few names and said to Huan Wen, "This matter requires careful deliberation. For instance, these men—are you certain?"
Huan Wen thought it over and decided that a temporary delay might be wise. He stood up to fetch a brush and inkstone from the next room, intending to strike out a few names. But as he pushed open the door, an unexpected gust of wind swept in, blowing the tent curtain aside—and there, in plain view, stood Xi Chao.
Xie An, seeing this, suddenly had an idea and seized the opportunity to excuse himself. He smiled at Xi Chao and said, "Master Xi truly deserves to be called a guest behind the curtain." Then turning to Huan Wen, he added, "The Grand Marshal had Xi Chao eavesdropping from behind the screen—what is the meaning of this? I take my leave!"
Huan Wen was deeply embarrassed, and his plan to kill had to be abandoned.
Thanks to a group of loyal ministers who steadfastly guarded the emperor, Huan Wen's ambition to usurp the throne ultimately failed to succeed.
Later, the idiom "Guest Behind the Curtain" came to refer to those involved in confidential matters, as well as close associates or advisors.
Source: *Book of Jin*, "Biography of Xi Chao"
Meaning of the Idiom: Later, the Chinese idiom "入幕之宾" came to describe those involved in confidential matters, as well as close associates or advisors.