The Forbidden City is also called the Forbidden City, which actually means "the old palace". This is the general name for the palace of the previous dynasty in history. It is said that at the end of the Spring and Autumn Period, when Lao Tzu, the founder of the Taoist school, was about to leave Hangu Pass, the gatekeeper saw purple energy coming from the east. Soon, Lao Tzu came from the east riding a green ox, and the gatekeeper thought he was a saint. . So the gatekeeper asked Laozi to write the famous "Tao Te Ching". Therefore, purple energy is considered to have auspicious meanings and also heralds the appearance of saints and treasures. In this regard, Du Fu once wrote a poem: "Looking to the west, the Queen Mother descends from Yaochi, and to the east, the purple air fills Hanguan." From then on, the ancients called the auspicious air Ziyun, and the place where the legendary immortal lived was convenient. It is called Zihai, the gods are called Ziquan, and the paths outside the city are called Zimo. As the saying goes, "Purple air comes from the east, symbolizing good luck." From this, we can see that the word "purple" in the Forbidden City has a great origin. And because the place where the emperor lived was heavily guarded and inaccessible to ordinary people, it was called the Forbidden City. Source: Enlightenment and Wisdom·Later Issue