The First House: The Self
The First House is considered by many people as the single most important house in the Zodiac because it rules the self. It reveals the personality. Who you are and what you will become is found in this House. Your health, attitude toward life, motivations, temperament and physical characteristics are ruled in the this House of the Zodiac.
A study of any planets that fall within the first house of your chart will help you to understand the many aspects of your personality. The planet said to Rule this house is Mars. If no planets fall in your First House you can learn much about your inner personality by studying this fiery planet. More insight can be garnered by reading about the sign of Aries which is aligned with this House.