In 781 BC, King Xuan of Zhou died, and his son Gong Sheng succeeded him, becoming King You of Zhou, the last monarch of the Western Zhou Dynasty. The year 782 BC marked the first year of King You's reign.
In the later years of King Xuan's reign, he overextended his military campaigns, became tyrannical and domineering, intensifying social conflicts in the Western Zhou dynasty. When King You of Zhou ascended the throne, he faced consecutive years of drought, and a major earthquake struck the capital Haojing and its surrounding areas, leaving the people suffering from hunger and cold, fleeing in all directions, leading to social turmoil, political instability, and a weakened state. Confronted with this situation, King You not only failed to strive for rejuvenation and salvage the declining Zhou dynasty but instead heavily relied on the flattering, greedy, and profit-seeking sycophant Guo Shifu, implemented "monopoly policies," and intensified the exploitation of the people, thereby sharpening class contradictions and inciting widespread resentment among the populace.
King You of Zhou was also excessively debauched, sending men everywhere to search for beautiful women. Grand Minister Yue Shudai admonished King You to attend diligently to state affairs, but King You of Zhou would not listen; with a single order, he dismissed Yue Shudai from his post and expelled him from the palace. Minister Bao Xiang, seeing such absurdity, was deeply dissatisfied and strongly urged King You to prioritize matters of state. Unexpectedly, King You of Zhou flew into a rage and, humiliated, ordered Bao Xiang to be imprisoned.
Bao Xiang was imprisoned for three years, and during this time, his clan in the Bao state exhausted every effort to secure his release. His son, hearing that King You was fond of beautiful women, launched a widespread search for a stunning maiden and indeed found a woman of celestial beauty. She had originally been an abandoned infant, adopted by a humble merchant couple, and raised in the Bao state. Bao Xiang's son had her elaborately adorned, gave her the surname Bao and the name Si, and then presented her to King You.
King You of Zhou saw Bao Si and was stunned by her heavenly beauty, becoming utterly infatuated with her. He immediately made her his consort and released Bao Xiang. After Bao Si entered the Zhou palace, King You cherished her like the apple of his eye, and she became the most favored woman in the entire royal court. From then on, King You indulged himself day and night in her company, leading a decadent and extravagant life, and increasingly neglected state affairs.
However, although Bao Si was born with a beauty that could make fish sink and geese fall, she did not like to smile. Even when faced with the magnificent palaces and luxurious food and clothing in the royal court, she never cracked a smile. King You felt it was a great pity that such a beautiful woman had no smile on her face. To win a smile from Bao Si, the ministers racked their brains and tried every possible method, but they could never let King You see her smile. Later, seeing that Bao Si never smiled all day, King You even offered a reward of a thousand taels of gold for any method that could make her show a smile.
One day, King You of Zhou went on an excursion to Mount Li near Haojing (present-day southeast of Lintong, Shaanxi). Along Mount Li, beacon towers were built every few li, totaling over twenty. During the Western Zhou Dynasty, to guard against invasions by the Quanrong tribe, beacon towers were erected from the capital to border fortresses. If the Quanrong attacked, sentries would immediately light the beacons to signal the feudal lords. Nearby towers would relay the fire, spreading the alarm. Thus, the lords would know the king was in danger and must raise troops to rescue him. Guo Shifu, seeing these towers, devised a plan to curry favor with King You. He suggested lighting the beacons to make the lords rush in vain, just to amuse Bao Si. The foolish king agreed, took Bao Si, and accompanied by Guo Shifu, ascended the beacon tower on Mount Li. With no enemy in sight, King You ordered the guards to light the beacons.
Once a single beacon was lit, warning smoke rose from all directions, and the feudal lords across the land, seeing the signal, believed the capital was under attack and swiftly led their troops to rescue the king. Upon arriving at the capital, they learned the king was at Mount Li and hurried there. But when they reached Mount Li, they found no enemy at all and were utterly bewildered. Only then did King You, from his high terrace, send someone to tell them: "There is no enemy—you have worked hard, you may return!"
Seeing the thousands of troops below rushing about in a flurry, Bao Si found it highly amusing and could not help but burst into laughter. The Records of the Grand Historian, in the "Annals of Zhou," records: "All the feudal lords arrived, but when they got there, there were no invaders, and Bao Si laughed heartily." King You was overjoyed that Bao Si had finally smiled and immediately rewarded Guo Shifu with a thousand pieces of gold. The weary feudal lords then realized they had been tricked—the beacon fire alarm was merely the king's way of entertaining his beloved consort with fireworks for amusement. Feeling deceived, the feudal lords were furious and led their troops back home. Later, to make Bao Si smile again, King You repeatedly lit the beacon fires, deceiving the feudal lords once more.
A year later, Bao Si gave birth to a son, and King You was overjoyed, naming him Bofu. The king became even more infatuated with her, and to please Bao Si, he recklessly disregarded ancestral rites and unjustly deposed Queen Shen and her son Yijiu from his position as crown prince, so that he could install Bao Si as queen and Bofu as crown prince. Grand Historian Boyang of Zhou, well-versed in historical records, sighed and said, "Great calamity is about to befall the Zhou royal house; its downfall is inevitable."
King You's original queen, Shen, was the daughter of the Marquis of Shen. After she was deposed, she took her son Yijiu back to the state of Shen and told her father, the Marquis of Shen, about King You's actions, which greatly angered him. Later, the Marquis of Shen heard that King You intended to strip him of his title and launch a military campaign against him. Deciding to strike first, in 772 BCE, the Marquis of Shen allied with the states of Zeng and the Quanrong barbarians to attack the Zhou dynasty, advancing all the way to its capital, Haojing. When the Quanrong forces actually reached the capital, King You panicked and urgently ordered the beacon towers to be lit as a warning. The beacons were lit, but no feudal lords came to the rescue. This was because King You had previously lit the beacon fires on Mount Li multiple times to please his concubine Bao Si, losing the trust of the feudal lords. Having been deceived repeatedly, the lords assumed that this foolish king was once again lighting the beacons merely to amuse his beloved, so they ignored the signal.
During the day, thick smoke billowed from the beacon towers, and at night, flames lit up the sky, yet no rescue troops arrived. At this point, King You of Zhou bitterly regretted his actions. The capital originally had few troops, so how could it withstand the massive invasion of the Western Rong forces from all directions? The Quanrong army breached Haojing, and King You, along with Bao Si, Bo Fu, and the royal treasures, hastily fled through the back gate of the palace, heading toward Mount Li. On the way, they were discovered by the Rong people; King You was killed, and Bao Si was captured. The fall of Haojing and the death of King You marked the end of the Western Zhou Dynasty, which had ruled for about 250 years.
It was not until the Quanrong tribes breached Haojing that the feudal lords realized the enemy threat was real this time, and they hastily united, leading large armies to come to the rescue. As soon as the allied forces of the lords arrived, the Quanrong plundered all the treasures accumulated by the Zhou dynasty over many years, set them ablaze, and then withdrew from Haojing.