Zhao Kuangyin was originally a general of the Later Zhou dynasty during the Five Dynasties and Ten Kingdoms period, holding the positions of Chief Inspector of the Palace Guard (the supreme commander of the imperial army) and Grand Commandant, thus controlling the military power of the Later Zhou.
In 959 AD, Emperor Chai Rong of the Later Zhou Dynasty died, leaving his seven-year-old son Chai Zongxun to inherit the throne, known historically as Emperor Gong of Zhou, with his mother Lady Fu honored as Empress Dowager.
On New Year's Day the following year, envoys from Zhen and Ding prefectures in the north arrived at court with an urgent plea: the Northern Han and Khitan had joined forces to invade, the border was in peril, and they begged for reinforcements.
Upon hearing the news, Empress Dowager Fu immediately summoned Chancellor Fan Zhi and others to discuss countermeasures. Fan Zhi recommended Zhao Kuangyin as commander-in-chief, with Murong Yanzhao as vanguard, and ordered the mobilization of military governors from various regions to lead the army north. The empress dowager agreed and promptly issued the imperial decree.
Zhao Kuangyin immediately mustered his troops and chose an auspicious day to march. Soon, the army arrived at Chenqiao Post. That day, an unusual atmospheric phenomenon occurred—as the sun set, a cluster of clouds appeared beneath it, resembling another sun.
Soon, a rumor spread through the army: there were two suns in the sky—one was about to set, foretelling the Zhou emperor's imminent abdication, while the other blazed with boundless radiance, heralding Zhao Kuangyin's rise to the throne.
Zhao Kuangyin's trusted advisor Zhao Pu, his younger brother Zhao Kuangyi, and loyal generals Gao Huaide and Yang Guangmei held a secret meeting, then split up to spread the word. At dawn the next day, soldiers gathered outside Zhao Kuangyin's tent. Zhao Kuangyi entered and said, "Brother, please rise and accept our congratulations."
Zhao Kuangyin was startled and said, "Is this acceptable? Let me consult the officers' opinions before deciding." Unexpectedly, as soon as he stepped out of the tent, the generals surrounded him and declared, "The army has no leader; we wish to honor you, Grand Commandant, as the Son of Heaven!"
Before Zhao Kuangyin could answer, Gao Huaide and the others had already brought forth the yellow dragon robe—an imperial garment reserved only for the emperor—and draped it over Zhao Kuangyin's shoulders. The assembled officers knelt as one, shouting, "Long live the emperor!"
Zhao Kuangyin declined, saying, "I have received such deep kindness from Emperor Shizong—how could I commit such an unjust act?" Zhao Pu urged him, "The Mandate of Heaven has spoken, and the hearts of the people are with you. If you refuse further, you will lose the army's loyalty. As long as you treat the young emperor with courtesy and honor the empress dowager, you can still repay Emperor Shizong's kindness." Seeing no other way, Zhao Kuangyin finally agreed. This was the famous "Chenqiao Mutiny" in history.
And so, Zhao Kuangyin ascended the dragon throne, founding the Song Dynasty and becoming known to history as Emperor Taizu of Song.
Later, the idiom "Robed in Imperial Yellow" came to describe being elevated to emperor by one's subordinates.
Source: *History of Song*, "Basic Annals of Taizu"
Meaning of the Idiom: Later, the Chinese idiom "黄袍加身" came to describe being elevated to emperor by one's subordinates.