The Blue Annals is a landmark in the historical literature of Tibet composed by a well known scholar and translator Gos lo-tsa-ba-gZon-nu dpal (1392-1481 A.D.). It is the main source of information for all later historical compilations in the ''Land of Snows''. This work is invaluable inasmuch as it establishes a firm chronology of events of Tibetan history and works out in detail the list of the names of famous religious teachers and their spiritual lineage. The work is divided into fifteen chapters, each dedicated to the history of a particular school or sect of Tibetan Buddhism. It provides a comparative study of the chronological data given by T`ang Annals, Blue Annals, and Tunhuang chronicles. The Blue Annals appears to be a faithful reproduction of the list given in the T`ang Annals with minor differences. The book concludes with the portrayal of the origin, etc. of the communities of the four schools. It contains indexes for Sutras and Sastras, Personal Names and Book Titles and Personal Names (Tibetan), etc.