http://www.travelchinaguide.com/cityguides/tibet/religion.htmBon was the indigenous religion of Tibet that, when partly absorbed by the Buddhist traditions introduced from India in the 8th century, gave Tibetan Buddhism much of its distinctive character.
Little was known to the outside world of this once flourishing religion until recently due to the fact that its followers were subject to severe persecution. With the growth in the popularity of Tibet as a tourist destination and an increasing interest in the region's history, studies have been carried out into the traditions of Bon.
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In order that their faith should not be entirely wiped out, the followers of the Bon doctrines introduced reforms and adopted aspects of Buddhism. Despite its suppression, Bon traditions survived under difficult conditions and continued to develop aspects of metaphysics, cosmology, philosophy and an extensive written canon. In 1998 a Tibetan Tibetologist produced statistics which showed that some 90 monasteries in the Tibet Autonomous Region, the majority being in Dengchen (a county in Chambo) had a population of some 3000 monks, about 90 reincarnated high monks and over 130 thousand Bon followers. In the main, there are now three Bon sects, these being the Old Bon, The Yungdrung Bon and the New Bon.