"Sword of Damocles" is a metaphor for two sides of things. When a person gains many honors and status, he has to pay the same price. In ancient Greek legends, it is used to metaphor and remind people to have a sense of crisis, and the alarm bell is always ringing in their hearts.

"Damocles" was the courtier of Dionysius II, the tyrant of Syracuse in the 4th century BC. He liked to flatter Dionysius very much. He flatters: As a great man with power and prestige, Dionysius is really lucky. Dionysius proposed to exchange identities with him for one day, so that he could try the fate of the leader. Damocles enjoyed being king at the banquet held in the evening. When the dinner was almost over, he looked up and noticed that there was only a sword hanging above the throne with a horsehair. He immediately lost interest in food and beautiful women, and asked the tyrant to let him go. He never wanted to get such luck again.

The sword of Damocles is usually used to symbolize this legend, which means that it is very unsafe to have great power, and it is easy to be taken away, or simply, it means that you feel the end is coming. The woodcut pictures of the sword of Damocles appeared in European book patterns in the 6th and 7th centuries.