Creator's Description: Confusion shrouds the events surrounding the death of Emperor Khri Srong lde btsan (742-c. 800) and the succession of his sons at the turn of the ninth century. Tibetan religious histories, Old Tibetan sources, and Chinese sources offer conflicting pictures of the order of events and the identities of those involved. Fortunately, a newly-published source, the Pangtangma Catalogue ('Phang thang ma), throws new light on the royal succession by referring to Mu rug btsan, the elder brother of Khri Lde srong btsan, as nothing less than an emperor (btsan po). Considering this new information alongside Old Tibetan inscriptional evidence, this article attempts to establish the order of events around Khri Srong lde btsan (742-c. 800)'s abdication and death, and to locate "Emperor Mu rug btsan" within them. (2007-11-18)