The beacon towers on hilltops often played a key role in military communication in ancient war times. Once the enemy pressed towards the border, the signal from the beacon tower would be sent by beacon (fires or lanterns) during the night or by smoke signals in the daytime.
A famous story is told about Baosi, Queen of the Western Zhou Dynasty (11th century BC – 711 BC). She was highly honored, yet she never cracked a smile. King You tried many ways to put a smile on her face, but he failed over and over again. He "called his court band to toll bells and beat gongs", and she looked unhappy. Then the band was asked to "play the bamboo flute and strings", and she remained displeased. Afterwards, "maids of honor served wine, festively singing and dancing", and she still did not smile.
"You don’t like music! What on earth are you fond of?" the King asked.
"I don’t have much of a liking for anything. But I can still well remember when I was a child. I liked to listen to the sound of colored silk being torn. It was clear and melodious," she replied. King You said in excitement, "That is very simple. Why didn’t you let me know that earlier?"
Then the King ordered the official property manager to produce colored silk. He assembled fresh and energetic maids of honor and had them tear the silk into pieces, but Queen Baosi remained unmoved.
"Why won’t you smile now?" he asked.
"I have not smiled so far," the Queen replied.
The King tried over and over again, but failed. In the end he gave an order: "Anyone, either in or out of court, who can amuse Queen Baosi will be awarded one thousand pieces of gold."
Afterwards, Guo Shifu, a treacherous court official, came and offered advice: "Set the beacon tower on fire and fool your sovereign rulers." That night the King and Queen reached Lishan Mountain by carriage, and gave the order. In a split second, the flames of the fire lit up the sky and the sovereign rulers moved their troops immediately to Lishan Mountain. There they found the King and Queen enjoyed drinking festively. The King then dispatched his bodyguard to inform them, "Everything is all right. I have just been joking with you." When they heard this, they looked at each other in blank dismay, leaving disappointed. Sure enough, Queen Baosi burst into laughter, stroking her hands when she noticed all the troops who had come in vain and now returned noisily. Accordingly, Guo Shifu got a prize of one thousand pieces of gold. Later, King You repeated his joke more often than not. In 771 B.C., Quan Rong (a then ethnic group) staged an armed rebellion against the Western Zhou dynasty. King You urgently ordered the beacon tower set on fire, but all the sovereign rulers did not come. Consequently King You was killed, and Baosi was taken away. The Western Zhou dynasty vanished. Hence come the Chinese idioms: "A single smile costs one thousand pieces of gold" and "The sovereign rulers are fooled by the beacon fire."