In 1952, Iyengar befriended the violinist
Yehudi Menuhin. Menuhin gave him the opportunity that transformed Iyengar from a comparatively obscure Indian yoga teacher into an international guru. Because Iyengar had taught the famous philosopher
Jiddu Krishnamurti, he was asked to go to Bombay to meet Menuhin, who was known to be interested in yoga. Menuhin said he was very tired and could spare only five minutes. Iyengar told him to lie down in
Savasana (on his back), and he fell asleep. After one hour, Menuhin awoke refreshed and spent another two hours with Iyengar. Menuhin came to believe that practising yoga improved his playing, and in 1954 invited Iyengar to Switzerland. At the end of that visit, he presented his yoga teacher with a watch on the back of which was inscribed, "To my best violin teacher, BKS Iyengar". From then on Iyengar visited the west regularly. In
Switzerland he also taught
Vanda Scaravelli, who went on to develop her own style of yoga. He taught yoga to several celebrities including Krishnamurti and
Jayaprakash Narayan. He taught
sirsasana (head stand) to
Elisabeth, Queen of Belgium when she was 80. Among his other devotees were the novelist
Aldous Huxley, the actress
Annette Bening, the film maker
Mira Nair and the designer
Donna Karan, as well as prominent Indian figures, including the cricketer
Sachin Tendulkar and the
Bollywood actress
Kareena Kapoor. In 1966, Iyengar published his first book,
Light on Yoga. It became an international best-seller. , it had been translated into 17 languages and sold three million copies. In 1967, the
Inner London Education Authority (ILEA) called for classes in "Hatha Yoga", free of
yoga philosophy, but including asanas and "
pranayamas (sic)" suitable especially for people aged over 40. The ILEA's Peter McIntosh watched some of Iyengar's classes, was impressed by
Light on Yoga, and from 1970 ILEA-approved
yoga teacher training in London was run by one of Iyengar's pupils,
Silva Mehta. Iyengar was careful to comply with the proscription of yoga philosophy, and encouraged students to follow their own religious traditions, rather than trying to follow his own family's
Visistadvaita, a qualified non-dualism within Hinduism. File:Yehudi Menuhin 43.jpg|In 1954, the violinist
Yehudi Menuhin invited Iyengar to teach in Europe. File:BKS Iyengar Centre House (cropped).jpg|Iyengar at
Iyengar Centre House, London, 1971 In 1975, Iyengar opened the Ramamani Iyengar Memorial Yoga Institute in Pune, in memory of his late wife. He officially retired from teaching in 1984, but continued to be active in the world of Iyengar Yoga, teaching special classes, giving lectures, and writing books. Iyengar's daughter,
Geeta, and son, Prashant, have gained international acclaim as teachers. Iyengar attracted his students by offering them just what they sought – which tended to be physical stamina and flexibility. He conducted demonstrations and later, when a scooter accident dislocated his spine, began exploring the
use of props to help disabled people practice Yoga. He drew inspiration from Hindu deities such as Yoga
Narasimha and stories of yogis using trees to support their asanas. He was however thought by his students to be somewhat rough with his adjustments when setting people into alignment; the historian of yoga
Elliott Goldberg records that, as well as being known for barking orders and yelling at students, he was nicknamed, based on his initials B. K. S., "Bang, Kick, Slap". In Goldberg's view, Iyengar "rationalized his humiliation of his followers as a necessary consequence of his demand for high standards", but this was consistent with his childhood response to the rough and abusive treatment he received from
Krishnamacharya, taking offence quickly, being suspicious of other people's intentions, and belittling others: "In other words, he sometimes behaved like Krishnamacharya". Goldberg concludes, however, that Iyengar hid "a compassion of which Krishnamacharya was never capable", and his students remembered his playfulness as well as his unpredictable temper. ==Philanthropy and activism==