“According to the great Tibetan scholar Lama Taranatha (sixteenth to seventeenth century) in his ‘History of Buddhism in India’, Vajrayana Buddhism can already be located in the time of Nagarjuna (first to second century) in the jungles of India, among a small group of isolated and anonymous meditators who followed this path to realization. These masters, known as siddhas (‘perfected ones’), were practitioners of the unconventional traditions of highest or innermost tantras. According to Lama Taranatha, these masters passed their lineages of practice and realization to only one or perhaps a very few disciples. Tulku Thondup Rinpoche says that ‘the Tantras of the Inner Yanas, the highest teachings of Buddhism, were introduced into India under the strictest secrecy.’ By the eighth century, we hear of the existence of eighty-four mahasiddhas, or ‘great siddhas’, who lived throughout India, following the Vajrayana traditions, and who taught, performed wonders, and transmitted the Vajrayana teachings to chosen disciples. As we shall presently see, the siddhas played a central role in the transmission of Buddhism to Tibet, and subsequently Tibetan siddhas carried on the teachings of their Indian counterparts in the Tibetan environment down to the present.
“The siddhas were men and women who, in their pretantric lives, often found themselves in situations of great distress, dislocation, and suffering. For them, as for Gautama Buddha, ordinary life held no hope of relief and no ultimate promise of satisfaction. Typically, they encountered a guru who accepted them as disciples and admitted them into Vajrayana practice through the abhisheka, or initiation liturgy. Subsequently, they spent many years practicing intensively. Sometimes their practice was carried out in cremation grounds or in solitary retreat. At other times it was carried out in the world, but secretly. Tantric gurus were known for their uncompromising and even ruthless approach to the spiritual path. Not infrequently they would place their disciples in difficult or degraded circumstances to teach them the renunciation of comfort, status, and security, and to free their minds for the ultimate. Eventually, their tutelage complete, the disciples attained realization and themselves became known as siddhas.
“The siddhas often brought their realization back into the world, where they pursued ordinary lives as men and women lay practitioners, representing all levels of society, working as kings, scholars, blacksmiths, sweepers, and so on. In this way, they used ‘ordinary life’ as the vehicle for their teaching and the transmission of their lineages. The eighty-four siddhas sometimes remained anonymous, appearing as unexceptional, unspiritual people within conventional society. At other times they exhibited their realization in shocking and unconventional ways. Sometimes they were called crazy (nyonpa), referring to their uncompromising expression of ultimate wisdom and compassion within conventional society, behavior that seemed ‘crazy’ by ordinary standards.”
[From Indestructible Truth – The Living Spirituality of Tibetan Buddhism by Reginald Ray]