Tradition credits the Nath lineage's teaching on bodily perfection to Gorakhnath, a figure scholarship treats as substantially legendary in the specific biographical details later hagiography attached to him, working in a guru lineage descending from Matsyendranath, and dates for both remain uncertain, placed by different scholars anywhere across the tenth to twelfth centuries. Wandering with Sadhus describes how Nath yogis organized into distinct monastic centers and wandering orders across North India that carried this teaching on physical transformation forward through many centuries of practice, developing a recognizable ascetic identity built around the pursuit of bodily siddhi, perfection, rather than around withdrawal from bodily existence. The Alchemical Body notes that a closely related body of teaching developed independently among the Siddha traditions of Tamil speaking South India, whose eighteen legendary Siddhars are credited in their own regional literature with comparable claims of achieving physical immortality or radical bodily transformation through practices that likewise blend yogic and alchemical vocabulary, a parallel development in a different linguistic and regional context rather than a direct offshoot of the North Indian Nath lineage. Elements of this teaching continue today in Siddha medicine, a formally recognized system of traditional medicine in South India that still draws on the same underlying claim that disciplined practice can refine and preserve the physical body well beyond its ordinary limits.