A number of prosopographic works on the military world have shown how beneficial such an approach might be in advancing our historical knowledge of various cultural areas at different periods. This conference aims to present and discuss an ongoing research project on the social history of the Tibetan army under the Ganden Phodrang government, based on the use of the prosopographic method. After outlining the corpus of available sources (autobiographies, public and private archives, oral sources) for the nineteenth and twentieth centuries, we will present the construction of the metasource as well as the broad lines of enquiry w propose to follow. A preliminary inquiry into the evolution of the Tibetan army officer corps was extended to the troops as a whole, from the base to the top of the hierarchy, with a comparative treatment of the various regiments that comprised the Tibetan army. The presentation will then examine a few specific examples of aspects of military history that the prosopographic approach can document and analyse: the contours of a military career, its variations according to different criteria the training of soldiers and officers, their origin and social mobility, the diversity of practices in regiments and, more generally, the evolution of the Tibetan military institution in the nineteenth and twentieth centuries.