One of my hobbies is collecting yoga instruction manuals published between the 1920s and 1966, the year of Mr Iyengar's Light on Yoga. From them I’ve made a kind of “timeline” for several poses, including Trikonasana and Urdhva Dhanurasana. The dozen or so “pre-Iyengar” poses look, shall we say, disorganized, on par with our stiffest, most beginning-est beginners.
Then suddenly, seemingly out of nowhere, there are Iyengar’s poses. There’s no obvious progression, as if it’s the culmination of a long evolution. It's rather a complete revolution in the presentation of the pose: the perfect integration of its parts, the harmony of its lines, the mastery of its expression. You can't help thinking, “This isn't an asana, it’s a piece of art.”
The two most important things he taught us with his work are that yoga—true yoga—doesn’t simply change us, it transforms us. Radically. And thus it helps each one of us express the unique beauty inherent in our being.