IC or cusp of Fourth House at birth

Definition

The IC, short for Imum Coeli or “bottom of the sky,” is the point where the local meridian reaches its lowest position beneath the horizon at the moment of birth. It stands opposite the Midheaven and is one of the natal chart’s four principal angles. In many quadrant house systems, the IC is also the Fourth House cusp, although some house systems place the two differently.

Astrological Meaning

In natal astrology, the IC describes a person’s private foundation: home, roots, family background, ancestry, and the inner conditions that support emotional security. Its sign may suggest the style in which someone seeks belonging or experiences domestic life. Planets near the IC can make these themes especially prominent, while the IC’s ruling planet provides further context through its sign, house, and aspects. Some traditions associate this angle with a particular parent, but practices differ, so the wider family environment is often the more reliable starting point.

Why It Matters

The IC helps distinguish public identity from private experience because it forms an axis with the Midheaven. It can clarify what restores a person away from social expectations and how early foundations continue to shape adult priorities. Interpretation should consider the Fourth House, nearby planets, the IC ruler, and the chosen house system. Because this angle depends on an accurate birth time and location, uncertain data may substantially alter its position.

Related Encyclopedia Entries

• Traditional Astrology
• Astrological Terminology
• Natal Chart
• Fourth House
• Midheaven