24 October 2013 Last updated at 20:45 ET By Jane O'Brien BBC News, Washington

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The BBC's Jane O'Brien attended the opening gala of Yoga: The Art of Transformation at the Sackler Gallery of Asian art

Early yogis struck lovely poses - and also fought fierce battles. An exhibit in Washington shows the complex dimensions of yogi life.

Do you like your yoga hot or powerful? Maybe you practise in the nude or spend a fortune on the latest Lycra. Are you a follower of BKS Iyengar, or do you prefer Vinyasa or Ashtanga yoga?

Whatever your taste, yoga is a $5bn (3.1bn) industry in the US practised by millions of people seeking physical fitness, improved health, or spiritual enlightenment. Almost every gym offers a class and the experience can be enhanced by drinking specially blended teas or listening to suitably soothing music.

The Indian government has become so concerned about the commercialisation of yoga in recent years that it started a campaign to patent hundreds of postures to stop them being appropriated by Western companies.

Yogis were seen as quite sinister and dubious figures

But the world's first exhibition exploring the visual art of yoga has revealed aspects of the ancient tradition that many purists will find troubling: in the 2,500 years of its known existence, there has never been one single type of yoga.

"Five years ago I did think I would find that single yoga tradition," says Debra Diamond, curator of the exhibition Yoga: The Art of Transformation at the Smithsonian's Sackler Gallery of Asian Art.

The rest is here:
Yoga history - savage and serene