Part of Marriage

Definition

The Part of Marriage is one of the Arabic Parts — calculated points — that classical and medieval astrologers used to look closely at marriage and partnership. Its most-cited formula goes back to Dorotheus, Carmen Astrologicum II.3 ("Venus to the degree of the seventh"): a single degree found by Ascendant + 7th-house cusp − Venus. Later Arabic and Latin sources catalogued several versions of the Part — some specific to men or women, some to a sub-topic — for example, Bonatti gives Asc + Venus − Saturn for men and Asc + Saturn − Venus for women. Which version flips by day or night varies from author to author.

In Tradition

In medieval Arabic-Persian and Latin practice the Part of Marriage is a precision-significator: it sharpens the broader reading you already get from the 7th house and Venus. Its sign and house, the condition of the planet that rules it, and the aspects reaching the Part itself describe the timing, the character, and the partner-quality of a marriage. Bonatti and the Sahl-Masha'allah chain of sources treat it as one of the topic-specific lots a practitioner turns to after the general partnership reading.

In Practice

You compute the Part by formula — commonly Asc + 7th cusp − Venus, or Asc + Venus − Saturn / Asc + Saturn − Venus by gender per Bonatti — then find its sign, house, and ruling planet. The usual reading takes the ruler's essential and accidental dignity (its inborn strength and its strength of placement) for partner quality, the house of the Part for the life-context it points to (10th house = a public match, 12th = a hidden one), and aspects from benefics or malefics for support or strain. In horary — chart-based question work — the Part is consulted for whether a marriage question "perfects," read alongside the rulers of the 1st and 7th houses. Because the sources hold competing formulas, traditional practice usually tests several Parts side by side rather than crowning one, and the ruler of the Part's triplicity adds timing detail in Dorothean three-thirds-of-life work.

Historical Origin

The Part of Marriage is recorded in Dorotheus of Sidon's Carmen Astrologicum II.3 (1st century CE) as "Venus to the degree of the seventh." It was carried through the Arabic transmission by 'Umar al-Tabari and Abu Ma'shar, set out formally in Bonatti's Liber Astronomiae (c. 1277, Tractate II Pars II), and entered the medieval Latin tradition through the per-Part formula catalogues that William Lilly summarises in Christian Astrology (1647).

Further Reading