The beginning of this biography is here.
He followed the teachings of yet another master, whom sMyo shul mkhan po calls mkhan po, the abbot. We read mkhan po ba in the mThong ba don ldan, and mKhon pa in Glag bla. mKhon is a variant of ’Khon, the name of the clan of Sa skya’s throne-holders; but the connection is too uncertain to make any sense. From this master he received the sGrub thabs rgya mtsho, the mKha’ ’gro rgya mtsho (Śrī Ḍākārṇavamahāyoginī-tantra rāja), the Prajñāpāramitā in 10,000 śloka, etc.
Klong chen pa was also the disciple of Karma pa Rang byung rdo rje (1284-1339), from whom he again received the Ṣaḍaṅgayoga of the Kālacakra “with the methods for removing obstacles” (gegs sel dang bcas pa), the Six Dharma of Nāropa, the Confrontation with the Threefold Body (sKu gsum ngo sprod), the rGyal ba rgya mtsho form of Avalokiteśvara and the so-called royal tradition (rGyal po lugs) of practicing this deity, the Guhyasamāja, the Saṃbhuṭi, the Mahāmāyā, the red (Raktayamarī) and black (Kṛṣṇayamarī)Yamāntaka, etc.
There is much to be said of this Karma pa, both as the focus around which much of the great religious Tibet of that time gravitated, and as our author’s forerunner in the combination of the two sNying thig, the mKha’ ’gro snying thig and the Bi ma snying thig. As for the Bi ma snying thig, Rang byung rdo rje received it in particular (but not exclusively) from Ku ma rā dza, who was also Klong chen rab ’byams’ main master. However, as far as mKha’ ’gro snying thig is concerned, it is through a completely different channel that this cycle of revelations (gter chos) came to him. I shall say something about this below in the short chapter on rGyal sras Legs pa, the disciple of Padma las ’brel rtsal (the main “inventor” [gter ston] of the mKha’ ’gro snying thig in the lineage that passed to Klong chen rab ’byams).
In this respect, it would be necessary to determine rigorously whether what is called Karma snying thig is simply the text entitled Nyams len lag khrigs ma’i khrid ngo mtshar can (Bi ma snying thig, pp. 260-329 in the section Man ngag nges pa), or whether this Karma pa undertook, before Klong chen rab ’byams, to compile the sNying thig by clarifying their obscure points. The Bi ma snying thig does not contain only one text by Rang byung rdo rje, but four. His presence can also be seen in the mKha’ ’gro snying thig, at least as the lineage holder.
The revelations of the “discoverers of treasures” (gter ston) are too often imagined from the example of Biblical or Koranic prophetism, in which God is supposed to address man with a message that was so far unheard of. In the ancient gter ma, if we take them according to a sort of structural approach, we have rather the feeling of dealing with fragments of an ancient tradition which is given piece by piece, some fitting with the others and completing them, like pieces of a puzzle, in which little by little the whole figure of the integral teaching takes shape. In this revelation, the numerous partial redundancies (texts found in two or more gter ma, often with some insignificant variations), far from being signs of incoherence, seem to indicate that the discoverers of treasures all draw from a common source, whatever its nature. In addition to historical research on the gter ma literature, it would be necessary to devote a sort of synchronic work to them, attempting to put these texts end to end and to connect them with the corpus of oral tradition (bka’ ma), in order to try to take the measure of this global textual system of the rNying ma school. This is, moreover, a project that is clearly in the making in the various editions of the rNying ma rgyud ’bum, insofar as they mix a large part of gter ma with the mass of tantra belonging to the bka’ ma tradition.
In any case, if it turned out that this textual puzzle could be arranged, and that it finally presents a coherent, homogeneous, logical and intelligible global figure, the spontaneous feeling that one can have, in view of the appearance of the gter ma, of an anarchic inventiveness under cover of personal inspiration, would perhaps be changed. This would in no way resolve the question of knowing where, in the final analysis, all this enormous mass of literature comes from; but, if, instead of appearing to us as a jumble of texts accumulated on a fairly coherent doctrinal background, it revealed to our eyes an intelligible architecture and a tightly woven network of internal references, this would, in any case, give us much to think about.
Returning to Klong chen rab ’byams and his relationship with the third Karma pa, Rang byung rdo rje, the biographies are not very rich in precise notations on the order of our author’s studies nor on his movements. It is therefore not known for certain whether he really received all of Rang byung rdo rje’s teachings during his time at gSang phu. However, if we can form a hypothesis based on the order of the narrative, since the entire catalog of teachings received is given before the narration of his sudden departure from gSang phu following his conflicts with khams pa monks, we can assume that it was in these years 1326-1332 that he was taught by Rang byung rdo rje. Our hypothesis concerning the association of the young Klong chen rab ’byams with Grags pa seng ge around 1326-1327 corroborates this assumption. Moreover, his life as a wandering ascetic in the years that followed, and the date of death of this Karma pa (1339) do not allow many other suppositions, especially insofar as the latter left mTshur phu for China between 1332 and 1335 and then in 1336, to stay there until the end of his life. Nothing excludes a priori, of course, another meeting in 1335-1336.
Read here the letter to Karma pa Rang byung rdo rje.
The next section is here.
 For a biography of this master in French, see Nik Douglas and Meryl White, Karmapa, le lama à la coiffe noire du Tibet, Archè, Milano, 1979, p. 45 ff. [and now Ruth Gamble, The Third Karmapa Rangjung Dorje, Master of Mahāmudrā, “Lives of the Masters”, Shambhala, 2020 ]
 Described by Gene Smith in the preface to vol. XXXIII of the Rin chen gter mdzod as “a union of the bka’ ma and gter ma tradition from the Myang tradition [i.e., the tradition of Nyang ral Nyi ma 'od zer] expounded in the Karma kam tsang tradition.” Some of these texts can be found in this volume of the gter mdzod, pp. 389-522.
 That of Srong btsan sgam po transmitted in the Maṇi bka’ ’bum and Ka khol ma, according to an indication by A. M. Blondeau. The text appears in the Rin chen gter mdzod (vol. XXXIII, pp. 1-275), where it is given as a gter ma of Nyang ral Nyi ma ’od zer.
 We give some examples here and there; the catalogs of the rNying ma rgyud ’bum given by Mi nyag Thub bstan chos dar in his rNying ma rgyud ’bum gyi dKar chag gsal ba’i me long (Beijing, 2000, kindly communicated by Katia Buffetrille) allow us to easily detect their presence. For example, the first text of the first volume of the sDe dge rNying ma rgyud ’bum, the sPros bral don gsal chen po’i rgyud (vol. Pa, pp. 2-288, in the mTshams-brag edition), is a gter ma by Guru Chos dbang, one of the fundamental texts of the Sangs rgyas mnyam sbyor.