Bhutan early history remains rather sketchy for want of proper records. Whatever was recorded was done in scriptures and was destroyed by fire and other natural disasters. Thus, much of Bhutan history draws from reports and personal diaries of British explorers and political officers, and legends and myths and folklore.
Many early inhabitants of Bhutan were followers of Bon, the animistic tradition prevalent throughout the Himalayan region before the arrival of Buddhism. Buddhism was first introduced to Bhutan in the 7th century AD by Guru Padmasambhava aka Guru Rinpoche, a tantric master.
He is supposed to have come to Taktsang in Paro riding a tigress. In fact, that how the most spectacular Taktsang Monastery came to be called the Tiger’s Nest.
Most Bhutanese historians, however, give Lama Phajo Drukgom Shigpo (1184-1251) the credit of establishing the Bhutanese form of Buddhism a the Drukpa Kagyu School. Lama Drukpa Kunley, the Divine Madman, visited Bhutan in the 15th century and established Chimme Lhakhang in Punakha.
Between the 11th and 16th centuries, numerous terma (sacred texts) hidden by Guru Rinpoche were discovered by tantric lamas called tertons. Terton Pema Lingpa discovered his first terma from the lake of Membartsho near Bumthang in 1475. While Bumthang is today considered the cultural heartland of Bhutan, Terton Pema Lingpa is considered a major figure in Bhutanese history.