What the Seventh House governs
The Seventh House is the house of the significant other: marriage and committed partnership, business partners, close allies — and, traditionally, open enemies and opponents (anyone we meet directly, face to face). Its cusp, the Descendant, sits opposite the Ascendant and describes the qualities we seek, project or attract in the people who complete the horizon of the self.
As an angular house it is powerful and relational; it is where the self learns it is not alone.
The Seventh House in the birth chart
The sign on the Descendant and its ruler describe the kind of partner a person is drawn to and the dynamics of their one-to-one relationships. Planets in the Seventh are lived out largely through others; Venus here seeks harmony in union, while Saturn may bring duty, delay or hard lessons through partnership.
The Seventh / First axis
The Seventh House of the other opposes the First House of the self across the horizon. Neither exists without the other: we discover ourselves through relationship and relationship through ourselves. Projection lives here — the traits we can’t own often arrive wearing a partner’s face.