Tulku is the Tibetan translation of the original Sanskrit term nirmanakaya. The term tulku has been translated as "the manifested-body, created-body, manifestation" or also as "incarnation, reincarnation, or rebirth." It has been translated into Chinese as huofo, which means "living buddha," and into Mongolian as qubilyan. Tulkus are the principal standard-bearers of the Buddhist tradition of Tibet and the providers of spiritual and social guidance for both the ordained and the laity. Tibetan buddhists have been meticulously following the tradition of finding, recognizing, enthroning, training, and venerating the tulkus for over a millennium.
In the literature and history of Tibetan Buddhism we can see three categories of the tulku. They are the emanations of the buddhas, the manifestations of the highly accomplished adepts, and the rebirths of highly virtuous teachers or spiritual friends.
First, there are the buddha manifestations, or the tulkus who appear to ordinary beings and serve them in infinite forms simultaneously through their fully enlightened power.
Second, there are the tulkus or the manifestations of highly accomplished adepts, who appear in many forms through the power of their highly realized wisdom.
Third, there are the rebirths, or tulkus, of virtuous or meritorious teachers, who are fulfilling their own spiritual goals and serving others through the beneficial effects of their virtuous deeds. Most of the tulkus of Tibet might belong to this third category, the rebirths of virtuous teahers or lamas.
Originally, tulkus were manifested by the enlightened power of the buddhas, as well as by highly accomplished adepts. However, Tibetan buddhists have also adopted the term and the concept of tulku for the rebirths of virtuous lamas. Buddhists of Tibet believe that buddhist masters will take rebirth after each of their deaths. In fact, Tibetan Buddhists trust that every being takes rebirth. And because they trust in karma, they believe that deceased lamas, who have accumulated virtuous karma, will obtain rebirths that enable them to benefit others. They believe that lamas obtain rebirths that enable them to benefit others because they trust in karma and know that the deceased lamas have accumulated virtuous karma. Tibetan buddhists believe that virtue, ore "merit," is the source of happiness and enlightenment, and that those who have attained this by leading virtuous lives will be sources of great benefit for many beings. They also believe that the tulkus of virtuous lamas will be sources of great benefit for many beings, because the lamas have led very virtuous lives, and virtue, or merit, is the source of happiness and enlightenment to Tibetan Buddhists.
Tibetan Buddhists also believe in the power of highly accomplished adepts to find the reborn manifestations of deceased lamas, because they trust in the power of highly realized wisdom-mind. Tibetan Buddhists enjoy full trust in the tulku tradition because it is based on mahayana fundamentals, and they have witnessed and appreciated an abundance of benefits from the good merit of tulkus
In most cases, a tulku is recognized by a highly realized lama before the tender age of four or five. Not long after they are recognized, their intensive training begins, and it can last for twenty years or more. They are generally educated under the watchful eyes of well-trained teachers in the best facilities available. Most tulkus are born with gifted qualities, but even if they are not, the chances of their becoming highly skilled teachers are very high because of the special attention and training they receive.
The main purpose of this tulku training is not so that they can qualify for a successful career, but so that they grow into skilled teachers and public servants who will serve the monasteries or nunneries and the whole society.
From Tibetan Buddhist literature we can learn about the profundity of the concept of tulkuhood in detail as taught by the Buddha, ancient Indian masters, and Tibetan scholars and adepts. The tulku system has offered unimaginable contributions to the spiritual, academic, and social world of Tibet. The imprints of the tulkus' lives — their writings, their teachings, and the institutions they have built — have become the main providers of education and spiritual civilization in Tibet, the Land of Snow, for centuries.