It was said that a peddler happened to find a baby girl who later became Bao Si.

About 782 B.C., King You of Zhou. King You turned out to be overly dissipated. When a minister tried to remonstrate him, he put him in jail. In order to rescue the minister, his family purchased Bao Si and traded her for him.

Since he had Bao Si, King You of Zhou had become even more negligent of state affairs, spending all his time with Bao Si. However, one thing about Bao Si made him unhappy she never smiled.

A sycophant minister of his, came up with an idea lighting the beacon towers on top of Mount Li (Mount of Black Stallion) and make a fool of all the vassal states.

Beacon towers had been used as warning signals against enemy attacks and to summon help. Fires or lanterns were used at night and smoke signals during the day. He assured the King that Baosi would smile when she saw that so many soldiers were fooled. The King agreed to try this plan. He took Baosi to Mt. Lishan, ordered his men to light the beacon towers and waited. When nearby rulers saw the flames in the sky, they thought the King was in danger and dispatched soldiers to his aid. King You then told them that it was only a joke. On seeing the disappointed soldiers scrambling to leave, Baosi burst into a smile. This made the king very happy. He rewarded Guo Shifu generously. The joke was repeated more than once.

But as a Chinese saying goes, "sadness usually follows extreme happiness." In 771 BC, the northern tribe of Quan Rong invaded his country. The King, as usual, commanded his soldiers to light the beacon towers, but by this time the other rulers had wised up and ignored his call for help. The king was killed and his beauty captured. The Western Zhou Dynasty collapsed and hence the legend of Great Wall beacon tower spread.