In the following 370 years after the downfall of the united Tubo kingdom, there was no powerful, united rule on the Qinghai-Tibet Plateau, so scholars call it "the divided and separatist ruling period". During this time, the two sons of Lhang Darma occupied separate areas.
Yundain and his descendants controlled Lhada and the Samye area, while Wosung occupied the Shannan area. In 905, Wosung was poisoned by his subordinate. His son Beikortsan fled to the Xigaze area, where he built castles and stationed his army. In 923, Beikortsan was killed by a rebellious army, after which his eldest son Zhaxizebarbe controlled Jamze, while his younger son Gyidenyimargung went to Pulan in the Ngari area. Later, the three sons of Gyidenyimargung separately controlled Ladakh, Pulan and Guge.
After the decline of the Tang Dynasty, in the Huang Shui River Valley of present Qinghai Province, there emerged a new local leader from the western regions, a tribal chief of the former Tubo Kingdom who established a regime called Gusiluo. The other parts of the plateau were ruled by various local leaders, who turned into separatist feudal lords. Some were newly emerged families and others descendants of nobles of the Tubo Kingdom. At the same time, land-holding peasants and herdsmen, faced with the fall of the Tubo Kingdom and the collapse of the tribal system, had to adapt to the new situation. Some lost their freedom when they were taken prisoner in wars, or went bankrupt after failing to repay their debts, while others willingly attached to those local leaders for protection. So the class of a tribe's common people who played the main role in social production gradually turned into a class of serfs dependant on local leaders, namely serf owners. Thus, feudal serfdom became widely established in various places of Tibet.
The period of divided and separatist rule after the collapse of the Tubo Kingdom saw the revival of Buddhism in Tibet, called in history the "Second Period of Dissemination of Tibetan Buddhism". When King Lhang Darma, the last king of the Tubo Kingdom, launched a movement to prosecute the religion, three Buddhist monks, namely Zang Rabsei, Joiqoinge and Mar Shakyamuni, fled to Qinghai to seek refuge in the Dando Monastery of Hualung County, where in 894 they accepted Laqin Goinba Rabsei as a disciple. At that time, as three Buddhist monks couldn't make up the required number to oversee an ordination, two other Buddhist monks from the Han areas were invited to attend the ceremony. Thereafter, around the Huang Shui River Valley there came into being a center of Tibetan Buddhism. About 936, Yeshe Gyaincain (the 6th generation of the Yundain lineage), local leader of the Samye area, sent Lumei Xirab Cechen and ten other Buddhist disciples to Qinghai to receive Buddhist ordination from Laqin Goinba Rabsei. Those ten Buddhist disciples returned to Tibet after they were fully ordained as Buddhist monks. Then, they made great efforts to advocate Buddhism by teaching disciples, rebuilding and renovating the monasteries. Many Buddhist monks and institutions were set up. In the history of Tibetan Buddhism, this is known as the "Lower Route Spread of Tibetan Buddhism". History books take the year of 949 as being when Lumei Xirab Cechen established Buddhist monks and institution in Lhasa as the starting point of the "Lower Route Spread of Tibetan Buddhism". Before long, Yeshe O, leader of the Guge Kingdom, contributed much to the revival of Tibetan Buddhism. He built several Buddhist monasteries and sent some young nobles to India to study Buddhism. Among of them there was the famous translator Renqin Sampo, No. 1 translator in the history of Tibetan Buddhism at that time, who went to India three times to study Buddhism. When he came back, he presided over the Tholin Monastery and devoted himself to advocating Buddhism. He translated Buddhist scriptures, taught disciples, and made every effort to revive Tibetan Buddhism. In the history of Tibetan Buddhism, this is called the "Upper Route Spread of Tibetan Buddhism"