This house is the marriage house, for the foundation of this house is the commitment of two people to one another. It is basically a contractual house. The seventh house includes all professional business partnerships and close collaborations with experts you hire, which often are covered by a written or oral contract. There is an implied confidentiality between the parties, and also, in an ideal world, where each person would hold an equal role in the relationship. (If the first house is “me” the seventh house is “thou.”)
An example of a relationship you might have in business would be the one you have with your business partner, agent, publicist, social media manager, doctor, lawyer, accountant—or even with an interior designer, landscape artist, or wedding planner.
Some people on the Internet write that the seventh house is the house of love, but that is not true, for love falls in the fifth house. In order for a relationship to fall in the seventh house, a serious commitment has to be made between both parties—oral, written, or unsaid but mutually understood. When two people wed or come together in business, they do so with a common goal in mind for their mutual benefit.
Oddly enough, this sector also rules open enemies but only when the planets in this house are badly aspected. Accordingly, this house rules lawsuits, if you have any. (You probably don’t because this sector would have to be virtually under siege with a barrage of unruly planetary activity to make this happen.)
For the majority of people, however, the seventh house, is most strongly indicative of the marriage partner and the sign on the cusp of seventh house in your chart suggests the type of person you might marry. (For example, if Sagittarius is found on that cusp, it might be a “Sagittarian type,” not necessarily a person born under the Sun sign of Sagittarius.)
The sign and planets in this house might also hint on how, or where, you would meet your marriage partner and describe the rapport between you that develops. For clues to a serious relationship, look at the fifth house too to trace the first spark of love—if things go right, the relationship will progress to the seventh house of commitment.
If you marry twice, then the cusp of the ninth house comes into play to describe the second marriage partner. If you marry a third time, astrologers look to the eleventh house, and so it goes around the horoscope, always skipping a house for a fourth and fifth marriage, if anyone would marry so many times. Still, as a professional astrologer, I would also look at the condition of the seventh house in any and all cases. If a couple is divorcing, it will show up in the seventh house with difficult aspects bringing the unhappiness of one or both parties to an apex.
The seventh sector is naturally ruled by gentle, refined planet Venus and the partnering sign of Libra. Keep in mind that Venus rules both love and money (hence, Venus’ association with the Second House).