While the founder Lama of Gelukpa sect was Tsongkhapa , his nephew Gendun Drup was the first Grand Lama .
Since then the mantle has been passed on to the subsequent Lamas under a Reincarnation theory of succession .
While the founder Lama of Gelukpa sect was Tsongkhapa , his nephew Gendun Drup was the first Grand Lama and since then the mantle has been passed on to the subsequent Lamas under a Reincarnation theory of succession .