A person with Mars in the 1st house is very active and energetic. The 1st house represents the first impression of a person, their appearance, behavior, style, and instinctive reaction to the surrounding world.
This placement shows that the person automatically strives to be a leader, to be independent and proactive. The sign of Mars will indicate how this activity manifests. Fire signs act on impulse and start acting immediately, while Earth signs will take a moment to look around but then push forward persistently, like a tank.
Regardless of the sign, it is important for this person to express themselves and be self-reliant. Even if they work within a structure, they will have something personal where they can assert their own line of behavior and insist on something.
Such a person is not afraid of responsibility. They usually speak their mind and can be direct. They may be prone to conflicts and easily get into arguments. It can be difficult to stop them once they get going, as their main focus is on expressing their own views, rather than considering what others say.
It is beneficial for this person to channel their active energy into positive outlets, such as sports, running, or physical work, otherwise it may come out through disputes and conflicts.
This placement works well in powerful professions like firefighting, emergency services, the military, law enforcement, or coaching, where this high activity can be maximized.
The physical appearance often reflects the Mars energy - a determined chin, heavy-set features that may be slightly protruding, thick and furrowed brows, muscular build, possibly a swarthy complexion, and coarse hair. Scars are also possible.