Songtsen Gampo's heir, Gungsong Gungtsen, died before his father, so his son, Mangsong Mangtsen, took the throne. His mother is sometimes said to have been a Chinese princess () but this is thought to be highly unlikely. His mother was most probably Mangmoje Trikar (), who is mentioned in the "Genealogy" found in the hidden library in the caves in Dunhuang, the "Tibetan Annals", which list the names of the Tibetan emperors and the names of their consorts who bore future emperors, and the clans they came from).