Nadi Astrology is a discipline used to discover one’s past and eventual fate of people with the help of antiquated palm leave manuscripts, made by Rishi munis around 1200 BC through their profound knowledge , and making use of one’s thumb creases to find related manuscripts to make predictions.
The 18 siddhars such as kalangi Nathar, Agasthyar, Konganaar, sivavakkiyar, Idaikadar, Bogar, etc. who influenced many Tamil literature and philosophy and would give solutions and advice to common people, who later decided to extend the service and help the future generations too by writing down unabridged texts about one’s life in palm leaf manuscripts regarding one’s past life, present and future at its entirety to help them their beyond time.
But these manuscripts needed some skills to decipher and understand in order to make proper valid predictions about future and it was believed that valluvars who served Pallava kings expertise at it and they started doing that as an occupation and helped many.