This period of Tibetan history, towards the end, and after the reign of Trisong Detsen is very murky and the sources give conflicting stories and dates.
When Trisong Detsen retired (c. 797) to take up residence at the Nyugmakhar Palace (sMyug ma mkar) in Zungkhar (Zung mkhar), he handed power to the eldest surviving son, Muné Tsenpo.
[3] The dBa' bzhed claims that Muné Tsenpo insisted that his father's funeral be performed according to Buddhist rather than the Bon rites.
After a short reign, Muné Tsenpo, was supposedly poisoned on the orders of his mother, Tsephongsa, who was jealous of his beautiful young wife, Queen Phoyongsa.
However, Sadnalegs elder brother, Mutik Tsenpo, had been apparently banished to Lhodak Kharchu (lHo-brag or Lhodrag) near the Bhutanese border for murdering a senior minister,[6] although some people believe he ruled for an indeterminate period.