Prince Siddhartha sat beneath the Bodhi-tree, meditated and through practice, became enlightened. Later as He taught, the four guardians kings, protectors of the dharma in the four directions, said: Whoever practices your dharma, we will give protection.
Usually by the front entrance of all Hinayana and Mahayana temples, images of these protectors are located on the walls. Also, during a retreat you invoke their protectors into statues or write their names on paper and even just on rocks. They will protect the area which you will use during the retreat.
When Lord Buddha taught Vajrayana in the form of Dorje Chang, Palden Lhamo and Mahakala offered their services to protect the higher levels of teachings. At this present time the Lama represents Buddha. The Lama shows you the three principle paths, and you practice these methods to clear away obscurations. We are lucky to be able to see the Lama in the form of a human being and not just as a dog as Asanga had.
Also the Lama teaches one the qualities of the yidam. These qualities are the casual and resultant paths of Buddhahood. The great teacher Toe-chen Chod-dorje came to the house of Gyalwa Ensapa, dressed in the clothes of a beggar. Gyalwa Ensapa though being young, yet due to some karmic linkage, was able to see through the disguise and requested teachings.
Toe-chen Chod-dorje gave teachings on the Existence of Life and Gyalwa Ensapa went on to attain Buddhahood. Toe-chen Chod-dorje also said to Gyalwa Ensapa to come to a certain mountain, and that he would endow him with something special. At this place Toe-chen showed his rainbow body and gave mandala explanations. Toe-chen is some what like Savari-pa and remains in this form of the rainbow body. If your karma is ripe you are able to see him.
Gyalwa Ensapa has said: whatever Milarepa practices I will also. He taught Guru-yoga-yidam Yamantaka. As he was passing away, his body shrunk. Before disappearing completely, his student Kedrup Sange Yeshe while prostrating requested him not to dissolve completely because sentient beings need to have a supreme object of refuge. Some people have relationships with gurus and these manifestations we can clearly see. The yidam being on a somewhat higher level, must be invoked many times for any sort of service. Yet, these yidams have servants whose position is to act as a vehicle for the yidam's wishes. These servants or sometimes dharma police have a closer relationship with people. When one wants to do a retreat, this servants or helpers of yours are very beneficial in clearing away obstructions.
Also, they have the power to awaken different kinds of siddhis which might be needed at certain times. Or, these protectors of yours might punish one if you break your commitments to them.
In this particular text, I have attempted to compile a history of the incarnations of Dorje Shugden, the protector of Je Tsong Khapa's teachings. To form a relationship with this protector one must have the Yamantaka empowerment. When actually receiving the initiation the initiator is manifested as Yamantaka. He is the contractor between you and the protector. Also the Lam Rim Scriptures are used as the witness of this contract, and the practice of Lam Rim makes Dorje Shugden happy.
In the stages of preparation of this history, the original presentation was by H.H. Zong Rinpoche and I, have added to it. With apologies for any inaccuracies, I hope that this text adds inspiration to those persons associated with Dorje Shugden.