Campanus Houses

Definition

Campanus is one of the ways of dividing a chart into twelve houses. It splits the prime vertical — the great circle running through the east and west points of the horizon and straight overhead and underfoot — into twelve equal 30° arcs, then carries each division onto the zodiac using great circles drawn through the north and south points of the horizon. The system is named after Campanus of Novara (1233-1296), the Italian mathematician credited with pinning down the construction, though the underlying geometric idea can be traced to earlier Arabic sources.

In Tradition

In medieval and Renaissance Western astrology, Campanus is one of the two main house systems built on the prime vertical, the other being Regiomontanus. Holden records that Campanus saw less actual use than Regiomontanus after 1490, chiefly because no comparable calculation tables had been worked out for it — not because anyone judged it doctrinally weaker. Modern surveys by Hand, Holden, and Houlding treat Campanus as a mathematically clean option whose popularity never rivalled Placidus or Regiomontanus.

In Practice

To build the in-between cusps, a Campanus chart finds the points on the prime vertical that sit 30°, 60°, 120°, and 150° away from the east point (and their opposites), then carries those points onto the zodiac with great circles drawn through the north and south points of the horizon. The cusps that result sit noticeably differently from Placidus and Regiomontanus, especially the further the birthplace is from the equator. Modern astrology software supports the system directly. Some twentieth-century writers — John Addey in his early work, notably — preferred Campanus for studying harmonic aspects, because of its prime-vertical foundation.

Historical Origin

Holden traces the system to Campanus of Novara (1233-1296), describing the construction as the trisection of the prime vertical, with great circles through the north and south horizon points cutting the zodiac to produce the cusps. The doctrine survived through Renaissance Latin treatises and was revived in twentieth-century Western practice by Charles E. O. Carter, Cyril Fagan, and others.

Further Reading

  • James H. Holden, A History of Horoscopic Astrology
  • Deborah Houlding, The Houses: Temples of the Sky
  • Robert Hand, Whole Sign Houses