ॐ गुरवे नमः
Dear Jyoti, Namaste.
The tenth house is the Indra Bhava and therefore is the strongest house in the entire chart followed by the Prajapati bhava (Lagna). So when a Graha is placed here it can completely eclipse all the other houses. It is the Simhasana (royal/lions throne) of the chart.
The three houses of the king are tenth, first and fifth in that order of strength. Among these the tenth house is also an upachaya indicating that this is where we appopriate our own free will… in other words where we use our brains instead of God’s.
So, when you have a Graha in the tenth house your life tends to revolve around it’s indications. The nature of the graha as well as its lordship become of prime importance to a person.
The only house which can control this tenth house is the house opposite, i.e. the fourth house, hence Parashara states that fourth lord in tenth house makes one इन्द्रजीत i.e. the one who conquers ones senses. In other words, the mana/mind (fourth house) if made strong through meditation and such practices can help control the senses and ensure that they do not indulge and bring about ripu (weaknesses, addictions, etc.).
Seventh lord in the tenth house is considered a Jara Yoga (Jataka Parijata) which brings about excessive passion and lust in matters of relationships.
I hope this clarifies.
Yours sincerely, Visti Larsen
Jyotish Guru (Vedic Astrologer)