Leo
Leo is fixed fire, the sign of high summer in the northern hemisphere, when the Sun's heat is an established fact and the question is how to sustain it. The image is the lion. Fixed signs hold. Fire signs hold a flame. Leo holds a flame in public: the heart as a center, the performance that is also a truth, the generosity that expects to be recognized because it is actually giving something.
The weather is radiant and central. It wants a clear self, a creative act, and a room in which that act can be received. Classical hot and dry temperament shows up here as warmth with a boundary. The sign is not only display. Display without a center is a different problem, and Leo's tradition is the center. The Sun does not borrow light. Leo, as the Sun's sign, prefers a life that can say what it is without a committee.
The Sun rules Leo. This is the Sun's only domicile. Vitality, authority of the heart, and the conscious will are at home in this weather. There is no separate classical exaltation parked in Leo in the standard scheme. The dignity story is the Sun's own sign, and the detriment of Saturn. Saturn is in detriment in Leo, opposite his domicile in Aquarius in the traditional rulership. Cold limit, delay, and the long no sit awkwardly in a sign that wants to shine and to give. Saturn can still work in Leo. He works by giving the radiance a spine: practice, a standard, a duration. The fall of the Sun is Libra, not a Leo story. The Sun's fall and Leo's topics are different pages.
The natural house is the fifth: children, pleasure, creation, games, and the risk one takes for joy. Traditional texts also put romance and the getting of honor here, distinct from the seventh house of the sworn partner. A planet in the sign of Leo wants to create or to be seen, in whatever house it occupies. Leo on the fifth is the natural match. Leo on the sixth describes a daily labor that still needs a heart in it.
Sun in Leo is the ruler at home. The conscious will is straightforward about wanting a life that feels alive and visible. Moon in Leo feels in a large way and looks for warmth returned. The feeling can be loyal and dramatic in the old sense of the word: acted, embodied, not hidden. The Ascendant in Leo makes an entrance that is hard to miss, and the reading of that rising sign needs a birth time.
Leo squares Taurus and Scorpio, and it opposes Aquarius. The opposition is the pair of the personal center and the wider circle, the king and the commons in an old political image that modern readers can take as heart and group. Fixed squares hold their ground on both ends. Trines run to Aries and Sagittarius. Fire recognizes fire, and the action comes freely. The risk of that ease is a performance that never meets a limit.
In practice, ask where the chart is asking to be warm on purpose. Leo's gift is a center that can give. Its risk is a center that can only receive. For the ruler, read the Sun. For the opposite principle of the group and the cold sky, read Aquarius and Saturn. For pleasure and creation, read the fifth house.