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What Is Synastry?
An astrological compatibility analysis

In Western astrology, there is a technique called “synastry”. It is done by laying a person’s chart on top of another’s to study their interactions. In this complex web of interpersonal dynamics, a very important thing to look at is how the key factors in a person’s chart are activated by the other person. Sometimes these factors could draw two people together very quickly, but as time goes by, the same factors could become sources of conflicts too.

Synastry: An Astrological Compatibility Analysis

Below shows the individual charts and synastry of former US President Bill Clinton and his wife Hillary. Bill is known to have multiple extra-marital affairs, but his marriage has somehow managed to survive. What can we see from their charts then?

Bill’s birth chart

Bill carries a Sun-Moon square in his chart, suggesting what is meaningful for him conflicts with what feels secure. To fulfil his life’s purpose, he finds it necessary to leave his comfort zone and support network, but that also creates a lot of uncertainly and anxiety for him. However, if he continues to stay in the comfort zone, life will seem stagnant and meaningless. So how does Hillary’s chart interact with his Sun-Moon square?

Bill Clinton's birth chart

How does Hillary’s chart interact with his?

The synastry below shows Hillary’s Saturn in Leo (outer wheel) conjoins Bill’s Sun (inner wheel), hence squaring his Moon at the same time too. In his eyes, she is very pragmatic, reliable, loyal and good at planning. In difficult times, she can give him staunch support. But she is also like a hard taskmaster for him, demanding compliance and even deference. As she is critical of anything he hasn’t done well, it is hard for him to relax and feel safe with her. So while Hillary’s Saturn provides him with concrete support, she has also heightened his inherent anxiety!

Synastry: Bill Clinton and Hillary Clinton

His Moon is in Taurus in the 8th house, indicating physical sexual contact is a main source of security for him. The synastry shows, however, sex is a very difficult area for the couple because Hillary has got a number of planets making hard aspects to his Moon. Those from her Mars and Pluto (and Saturn as mentioned) are especially tough, for they all show Bill finds it hard to relax and be himself when with her. There is a regular fear that he may somehow upset her.

How's Hillary’s chart activated by his?

What about Hillary (inner wheel)? She is actually very sensitive to his moods (his Moon falls on her Descendant). If he seems awkward and tries to distance himself from her, she can sense that immediately and tempers flare up. This is because Bill’s Sun-Moon square also sets off an important configuration in Hillary’s chart, i.e. the square between the Scorpion stellium (Chiron, Venus and Mercury) and another one in Leo (Mars, Pluto and Saturn). This means in her eyes, he is often selfish, arrogant, needy and ungrateful, making life very tough for her. His presence could easily trigger a buried rage in her and she feels she cannot get his attention unless she is angry!

Synastry: Hillary Clinton and Bill Clinton

This is how a vicious cycle ensues: The angrier she is, the less safe he feels, the more distant he becomes, etc. And his extra-marital affairs certainly haven’t helped things either.

What areas do they affect each other the most?

Synastry also shows the area(s) in which two people affect each other most deeply.

Figure A shows Bill’s chart in the inner circle, with Hillary’s on the outer. Figure B shows the reverse. Most of his planets fall in her 9th and 11th houses, indicating areas in which Hillary is most influenced by her husband: Foreign relations, travels and cultures, religion, philosophy, etc are all 9th-house matters. The 11th house is the “house of friends” and also of social and political issues. For Bill, Hillary’s planets pack his 2nd and 11th houses (too), suggesting she exercises the greatest impact on his finances (2nd house), social circle and politics (11th).

Synastry: When a partner's planets fall into your houses

No surprise for a power couple that both have deeply influenced each other’s politics, as indicated by the mutual 11th house emphasis by each other’s planets. This is probably why despite Bill’s multiple affairs, the couple has stayed together nevertheless: They are each other’s best friend and comrade-in-arms, with a shared vision for politics and society, though emotionally speaking, their relationship is anything but smooth-sailing.


In addition, there is clearly one area in life for Bill that without Hillary, he probably would not have made it or made it this far – Money! His 2nd house is empty by birth, suggesting this is not something he naturally focuses on. But a shared life with Hillary who has got as many as four planets occupying this house of his makes money (and materialistic stability in general) an important concern for him in life.


For example, because of Hillary’s encouragement and insecurity about finances (her Chiron, Venus and Mercury stellium in Scorpio plus Jupiter in Sagittarius in his 2nd house), he might find it necessary to develop his talents to bring in more money, perhaps particularly so at the beginning of their marriage. This is a very good example of how a long-term, intimate relationship with someone else literally changes the course of our lives!

To sum up

The chief function of synastry is to help people understand where they can most easily get along, where conflicts may arise and most importantly, what inherent tendencies each partner activates in the other, that may result in a chain reaction and even a vicious cycle of relating. With awareness, both parties can choose alternative responses and stop the cycle.

Do you want to learn more? Check out my chart-reading services, including synastry!

Chart-reading services

Or, you want to read charts for yourself? Check out my one-to-one astrology private classes, from beginners' to advanced levels, including synastry by clicking the pictures below:

Astrology class for beginners: Uncovering potential in birth chart
Astrology class for intermediate level: Transits and Synastry
Astrology class for advanced level: Integrated reading of birth chart and tricky charts

About Belinda

Astrologer Belinda's bio

Belinda has got over 10 years of chart-reading experience and holds four university degrees, including Psychology and Counselling. Before becoming a professional astrologer, she was doing a highly stable and well-paid job. She switched because astrology had simply changed her life... 

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