Tibetan Buddhist histories say a monk shot Emperor Langdarma in 842; his two sons by different queens split the empire

Langdarma reigned from about 838 to 842. Later Tibetan Buddhist histories say he persecuted Buddhism. They say the monk Lhalung Pelgyi Dorje was told in a dream by a goddess to kill him. He blackened a white horse with coal, wore a cloak black side out, hid a bow in its sleeves, and shot the king while bowing before him. He escaped by turning the cloak white side out and riding through a river so the coal washed off. Non-Buddhist texts from Dunhuang of about the same age do not mention the killing, and one says Buddhism flourished in his reign. The scholar Zuiho Yamaguchi argues the persecution story may be distorted and the assassination possibly fictitious. He left two sons, Yumtän and Ösung, by different queens. Their supporters fought, and the empire broke into small states ruled from fortresses. Ösung's line went west and founded the kingdom of Ngari. Its king Yeshe Ö became a monk and founded Toling monastery in Guge in 996. The sources disagree on which queen was senior.