How the Forbidden City Got Its Name

When the Ming court built its palace compound in Beijing in the early fifteenth century, it named the complex Zijincheng, the Purple Forbidden City. The purple is not the colour of its walls, which are red; it is the purple of Ziwei, the Purple Forbidden Enclosure around the pole of the sky. The name declares a correspondence: as the celestial emperor dwells at the unmoving centre of the heavens, so the earthly emperor dwells at the centre of the realm, and the palace grounds were closed to ordinary subjects as the circumpolar palace is closed to ordinary stars. The correspondence ran through the city's whole plan, with the palace on a north to south axis and the throne facing south, the direction a sovereign faces because the pole stands at his back.

The habit is much older than the Ming. Chinese political cosmology had long described the ruler by the pole: the Analects already say that one who governs by virtue is like the north star, which keeps its place while the multitude of stars turn about it. The enclosure also lends its name to Zi Wei Dou Shu, the purple star astrology that this atlas records among the divinatory disciplines, which organises a birth chart around the pole star Ziwei as the sky organises itself around the pole. One name, borrowed twice, for a palace, a city and a fate.