Tutelage Under Krishnamacharya
At the age of 15, Iyengar went to live with his brother-in-law, the well-known yogi Sri Tirumalai Krishnamacharya, in Mysore. There, Iyengar learned asana practice, which steadily improved his health.
Though BKS Iyengar has very high regard for Krishnamacharya, and occasionally turned to him for advice, he had a troubled relationship with his guru during his tutelage. In the beginning, he predicted that the stiff, sickly teenager would not be successful at Yoga. He was neglected and tasked with household chores. Only when Krishnamacharya's favorite pupil at the time, Keshavamurthy left one day, did serious training start. Krishnamacharya began teaching a series of difficult postures, sometimes telling him to not eat until he mastered a certain posture. These experiences would later inform the way he taught his students.
Read more about this topic: B. K. S. Iyengar