A tulku is a reincarnate custodian of a specific lineage of teachings in Tibetan Buddhism who is given empowerments and trained from a young age by students of his or her predecessor. High-profile examples of tulkus include the Dalai Lamas, the Panchen Lamas, the Samding Dorje Phagmos, the Karmapas, Khyentses, the Zhabdrung Rinpoches, and the Kongtruls.
Nomenclature and etymology
The word སྤྲུལ or 'sprul' was a verb in Old Tibetan literature and was used to describe the བཙན་པོ་ btsanpo taking a human form on earth. So the sprul idea of taking a corporeal form is a local religious idea alien to Indian Buddhism and other forms of Buddhism. Over time, indigenous religious ideas became assimilated by the new Buddhism; e.g. sprul became part of a compound noun, སྤྲུལ་སྐུ་'sprul.sku'. The term tülku became associated with the translation of the Sanskrit philosophical term nirmanakaya. According to the philosophical system of trikaya or three bodies of Buddha, nirmanakaya is the Buddha's "body" in the sense of the bodymind. Thus, the person of Siddhartha Gautama, the historical Buddha, is an example of nirmanakaya. In the context of Tibetan Buddhism, tülku means the corporeal existence of enlightened Buddhist masters in general. In addition to Tibetans and related peoples, Tibetan Buddhism is a traditional religion of the Mongols and their relatives. The Mongolian word for a tülku is qubilγan, though such persons may also be called by the honorific titlequtuγtu, or hutagt in the standard Khalkha dialect. According to the Light of Fearless Indestructible Wisdom by Khenpo Tsewang Dongyal: the term tülku "designates one who is 'noble' and used in Buddhist texts to denote a highly achieved being who has attained the first bhumi, a level of attainment which is truly egoless, or higher." The Chinese word for tülku is huófó, which literally means "living Buddha" and is sometimes used to mean tülku, although the Dalai Lama has said that this is a mistranslation, as a tülku isn't necessarily a realized being.
Meaning of "tulku"
Any Vajrayana practitioner can be reborn as a tülku, if they fail to reach Buddhahood or a Pure Land in the bardo of dying, bardo of dharmata or bardo of becoming. Valentine summarizes the shift in meaning of the wordtülku: "This term that was originally used to describe the Buddha as a "magical emanation" of enlightenment, is best translated as "incarnation" or "steadfast incarnation" when used in the context of the tulku system to describe patriarchs that reliably return to human form."
Finding a successor
Pamela Logan outlines a general approach for finding a successor:
Training
Logan describes the training a tulku undergoes from a young age: The academic atmosphere is balanced by unconditional love:
History
The tulku system of preserving Dharma lineages did not operate in India. The first tulku line of Tibet is the Karmapas. After the first Karmapa died in 1193, a lama had recurrent visions of a particular child as his rebirth. This child was recognized as the second Karmapa, thus beginning the Tibetan tulku tradition.