Astrology basics

Chart ruler

The chart ruler is the planet that rules the sign on the ascendant — for an Aries ascendant, for example, the ruler is Mars.

Its sign, house placement, and the aspects it forms with other planets are treated as especially significant — almost a "narrator" for the whole chart, since it links the ascendant's theme (how a person steps into the world) with the theme of whatever house and sign it occupies itself.