King Tri Ralpachen
King Tri Ralpachen (9th Century). The Dharmaking Trisong Detsen had three sons. The older was Mune Tsepo, the middle one Murup Tsepo, and the youngest Mutik Tsepo. All three also spread the Buddhist teachings. Tri Ralpachen was one of the five sons of Mutik Tsepo who was said to be an emanation of Vajrapani. He was extremely devoted to the teachings of the Buddha and was famous for having built one thousand temples.
He invited many scholars from India, like Surendrabodhi, Shilendrabodhi, Danashila. And to them and the learned masters from Tibet such as Ratnarakshita and Dharmadashila, as well as the lotsawas Jñanasena and so on, he said:
“When the teachings were translated at the time of my forefathers, the scholars used many terms unknown to the Tibetan language. Change those which contradict the teachings or the rules of grammar, and the difficult to understand by using preferably familiar terms of colloquial Tibetan. Revise in this way the translations of the Mahayana and Hinayana texts.”
Accordingly they revised the translations, such as those of the Prajñaparamita. Yet since the meaning of the inner tantras cannot be grasped by ordinary persons they did not revise them. (Based on the History of the Dharma by Dudjom Rinpoche [bdud 'joms chos 'jung]).