Tiber's decentralization had contributed to the establishment for the different Buddhist sects, and it was the revival of religion rather than the emergence of a new royal line that sought to bring unity to the Tibetan plateau. In the thirteenth century, this state of decentralization came to an end when Pagpa, the abbot of Sakya, unified the whole of Tibet with the support of the Yuan Dynasty.

In the fourteenth century, as the strength of the Sakyapa Sect gradually diminished, an armed struggle for political and economic paramountcy one again emerged among the different cliques, with the Pagdu Kagyupa Sect at the head. Pagdu Changchub Gyaltsan with an army from Lhoka annexed the Tsalpa and Drikung myriarchies in U and at the same time, taking advantage of internal troubles among the Khon clan of the Sakyapa Sect, attacked the Sakya Monastery and seized control of most of the region of Tsang. Subsequently Pagdu's regional administration was set up and received recognition from the Yuan Dynasty, the Yuan Emperor Shun Di conferring the title of Da Situ on Changchub Gyaltsan.

It was at this time that Tsongkapa came to Tibet in quest of Buddhist studies so as to keep the Wheel of the Law ever turning. Tibet by now was in a state where different religious sects were attaching them-selves to different regional feudal powers and making mutual use of one another. Under the mantle of religion some rulers seized both political and religious power. Politically arrogant and domineering, they brooked no opposition and plundered and seized great amounts of wealth. Their lives were given over to ease and comfort, while the people met only with suffering and misery. Production too suffered loss and damage, and peace and security were urgently needed. More-over, while the Sakyapa and then the Kagyupa sects held sway, there was relaxation of religious discipline which opened the way to all kinds of abuses. Monks and lamas in power together with their many followers neither recited prayers no observed monastic rules, but gave themselves over to drinking, gambling robbery, and licentiousness, committing all kinds of outrages. The prestige of Buddhism fell considerably, and had things continued in this way Buddhism would indeed have suffered a crisis of faith.

It was under such circumstances that Tsongkapa launched his religious reforms. Originally from Amdo (Qinghai), Tsongkapa at the age of sixteen traveled around various regions of Tibet, paying homage to the Sakyapa, Kagyapa and Kadampa sects and acknowledging their high lamas as his own masters. With the energetic support of Pagdu's administration, he found-ed a new sect, the Gelugpa, which was based on discipline and laid equal stress on philosophy and tantric mysticism. The direct successor to the Kadampa sect, it took all the strong points of the other sects and welded them into one.