Thubten Lhundup Legsang (1918–1990) was the twelfth in a line of tulkus from Dhartsendo in Eastern Tibet. The previous tulku, also hailing from Dhartsendo, had been a Nyingmapa tulku but had taken education in the Gelugpa’s Drepung Monastery and had become its main abbot. Bhante Sangharakshita’s respect and admiration for Dhardo Rinpoche was not on account of it being said that Rinpoche was a 'high tulku' of the Gelugpa tradition, but because over a number of years he saw directly that Rinpoche embodied the qualities of the six Buddhist pāramitās or ‘Perfections’.
After Sangharakshita had known Rinpoche for nearly ten years and had come to revere him as a living Bodhisattva, he requested the bestowal of the Bodhisattva Ordination which Rinpoche gave on 12 October 1962. Rinpoche also initiated Sangharakshita into the White Tārā and Medicine Buddha sādhanas.