The Sun archetype
The Sun is the centre of the chart as it is the centre of the solar system: the source of light, life and coherence. It represents the essential self — the conscious will, the sense of "I am", the vitality that animates the whole. Where the other bodies describe functions of the psyche, the Sun describes the self those functions serve.
Its archetype is the sovereign and the hero: the principle that seeks to shine, to individuate, and to become fully what it is.
The Sun in the birth chart
The Sun’s sign shows the core quality of identity a person is here to develop; its house shows the arena of life where they are meant to shine and find purpose; its aspects show how easily the self integrates the rest of the psyche. A well-supported Sun gives confidence and vitality; a challenged Sun often marks a life-long project of earning one’s own light.
Rulership and dignity
The Sun rules Leo, the sign of creative self-expression, and is exalted in Aries, where identity asserts itself through action. It is in detriment in Aquarius and fall in Libra — the signs of the collective and the other, where the singular solar self must learn to share the stage.