Bellur Krishnamachar Sundararaja Iyengar, born on 14 December 1918, was a renowned Indian yoga teacher and author. He was the creator of "Iyengar Yoga," a popular style of yoga that focuses on physical alignment and was considered one of the world's foremost yoga teachers. Iyengar was a prolific author who wrote many books on the philosophy and practice of yoga, including Light on Yoga, Light on Pranayama, Light on the Yoga Sutras of Patanjali, and Light on Life. He was a student of Tirumalai Krishnamacharya and is known to have popularized yoga first in India and then around the world.

In recognition of his contributions, the Indian government awarded Iyengar the Padma Shri in 1991, the Padma Bhushan in 2002, and the Padma Vibhushan in 2014. He was also named one of the 100 most influential people in the world by Time magazine in 2004.