Old Tibetan documents are the oldest extant monuments of the Tibetan language. Their exploration, although successfully flourishing in the last two decades, has been considerably impeded by often unintelligible and obsolete vocabulary that was bound to the particular cultural and political context of the Tibetan Empire that collapsed in the 840s CE. The present publication aims at clarifying a part of this vocabulary by examining nearly 400 Old Tibetan compounds. In Part I an attempt has been undertaken to define a compound and to provide the first linguistic classification of Old Tibetan compounds. Part II concentrates on a lexicological analysis of the compounds and strives to