[1] The Phagmodru hermitage, situated on the northern bank of the Tsangpo River, was founded by Phagmo Drupa Dorje Gyalpo (1110–1170) who initiated a sub-sect of the Kagyu school of Buddhism.
One was Phagmodru with the palace of Nêdong as its center; it was headed by a lord of the Lang Family who bore the title tripon (myriarch).
[4] Changchub Gyaltsen was born into the Lang lineage in 1302 as the son of Rinchen Kyab and his second wife Tramon Bumkyi.
Changchub Gyaltsen was appointed to the post, receiving a seal with a tiger's head by the great khan Sidibala.
The tripon took care to rule according to Buddhist principles and enjoined his retainers to avoid alcohol and afternoon meals.
A Sakya official called Wangtson captured Changchub Gyaltsen at a banquet in 1336 and demanded that he cede the lordship of Phagmudru to a spurious "cousin".
Now the ponchen Gyalwa Zangpo arranged a meeting at a bridge but proceeded to capture Changchub Gyaltsen in the middle of the deliberations.
However, Changchub Gyaltsen's retainers refused to give up the place, and the prisoner was tortured and brought back to Sakya.
Gyalwa Zangpo heard that the great khan Toghon Temür would replace him as ponchen with the ambitious Wangtson.
Shortly after, Wangtson took charge of the governance of Central Tibet and gathered Tibetan and Mongol soldiers to attack Phagmodru.
Though outnumbered, the troops of Changchub Gyaltsen repelled the Sakya attacks and began to occupy disputed neighboring areas.
Gyalwa Zangpo, who had regained the ponchen-ship in c. 1350, was hard pressed by the troops of Nangpa and in his desperation asked Changchub Gyaltsen "to uphold the law".
[17] Still it is clear from Changchub Gyaltsen's own autobiography that he encountered some opposition up to at least 1361, and that Sakya was still considered superior de jure, if not in fact.
[18] At any rate Changchub Gyaltsen stood out as the de facto ruler of Central Tibet towards the end of his life – several years before the Ming dynasty was established in China in 1368.
Central China was wrecked by rebellions after 1354, so that the great khan of the Yuan dynasty had little time to spare for Tibetan affairs.
It was something of a golden age in the history of medieval Tibet due to the relative inner peace and the great cultural achievements.
A law code was promulgated in 15 chapters and was supposedly so effective that an old woman carrying a load of gold could travel securely through Tibet.
He entertained good relations with well-known religious scholars such as Buton Rinchen Drub, Gyelse Thokme and Lama Dampa Sonam Gyaltsen.
Of worldly constructions, he founded a number of dzong (castles) such as Chaktse Drigu, Olkha Taktse, Gongkar, Nêdong, Drakkar, Rinpung, Samdruptse, Panam, and Lhundruptse.
They were followed by four generations of Tsangpa kings who ruled from 1565 to 1642, until Lobsang Gyatso, the 5th Dalai Lama (1617–1682), took control of Tibet and established the Ganden Phodrang regime with the support of Güshi Khan (1582–1655), a Mongol ruler of Kokonor and founder of the Khoshut Khanate.