Tadrak Rinpoche Ngawang Sungrab (Tib. སྟག་བྲག་རིན་པོ་ཆེ་ངག་དབང་གསུང་རབ་, Wyl. stag brag rin po che ngag dbang gsung rab) (1874-1952) served as tutor to His Holiness the Dalai Lama and gave him his vows as a novice monk. He accepted the regentship of Tibet in 1941, resigning in 1950, aged seventy-five, when the Dalai Lama was offered full authority over Tibet. He transmitted the Fifth Dalai Lama's Sangwa Gyachen cycle of revelations to His Holiness.