Astronomically speaking, the fourth house is that one-twelfth sector of the local sky counter-clockwise from the nadir (see above picture) occupied by planets in the two hours before they reach the lowest point in the local sky.

The fourth house rules the home, our family as a child and as an adult, the nurturing parent and our early experience of being nurtured, our most personal and intimate life, real estate and property, and our heritage and ancestry. Here is where we send down roots and establish a base of operations, find our limits, and generally secure ourselves. It is the end of any searching we might have done in the Third house, and thus rules the latter part of life. A planet here indicates the need for a stable emotional base in order to fill the needs of the house it rules. The more planets in this house, the more one tends to be subjective, personal, private or introverted.