Before the introduction of Buddhism in Bhutan, the prevalent religion was Bon.
Some scholars hold that Bön doctrine became so strongly reinvigorated in Bhutan by Buddhism that by the eleventh century it reasserted itself as an independent school.
Scofield (1976: p. 669), one of the first western journalists into Bhutan, outlined that:One Sunday I watched the monks shape an elaborate offering of dough and colored butter and put it atop a roof...as a treat for the ravens.
Killing a raven, he informed me, would be as great a sin as slaughtering a thousand monks...The dough offering is what is known as a torma.
The sacred syllable a, the first letter and sound of the Sanskrit and Tibetan languages, is a bīja mantra about which volumes have been written in Hinduism, Bon and Vajrayana.