Cancer rules the fourth house of the home and roots. If you look at the zodiac wheel, you’ll notice that Cancer’s fourth house sits at the bottom, literally acting as the anchor and foundation of the entire circle. Cancers feel a very strong connection to family and home, and truly believe that home is where the heart is. Because of that, Cancers are extremely interested in their ancestors and often do extensive research into genealogy.
The fourth house also rules privacy, security, and the overall concept of being safe. This can mean in both an emotional and physical sense. It’s very important for Cancers to have that safe feeling in all areas of their life. Because they are introverted and have a tough outer shell, if a Cancer lets someone into their sacred space (especially their home), it will be almost impossible for them to forgive anyone who breaks their trust and violates their peaceful house in any way.