Patanjali's systematic 196-aphorism text turning yoga's scattered older practices into a single coherent path — the ashtanga, eight-limbed structure still taught in yoga instruction worldwide.
लगभग २री शताब्दी ई.पू. · circa 2nd century BCE
The Sutras open by defining yoga itself as the stilling of the fluctuations of the mind, then lay out eight limbs progressing from ethical restraint (yama) and observance (niyama) through posture (asana) and breath control (pranayama) to concentration, meditation, and finally samadhi, absorption.
Though composed as a philosophical text rather than a physical manual, the Sutras' framework underlies almost every modern yoga tradition's claim to authenticity, and its opening definition of yoga is still quoted at the start of teacher-training courses worldwide. Patanjali himself is covered separately in this site's Rishi Parampara chapter.