พระเจ้าลางทรมา

Darma U Dum Tsen (), better known as Langdarma (, "Mature Bull" or "Darma the Bull"), was the last king of the Tibetan Empire who in 838 killed his brother, Tritsuk Detsen, then reigned from 841 until his assassination in 842. His reign led to the dissolution of the Tibetan Empire, which had extended beyond the Tibetan Plateau to include the Silk Roads with the Tibetan manuscript center at Sachu (Dunhuang), and neighbouring regions in China, Afghanistan, and India. He was assassinated by a Buddhist monk Lhalung Pelgyi Dorje.