Synopsis Ladakh region of Jammu & Kashmir, and Lahul & Spiti and Kinnaur districts of Himachal Pradesh combined together form a distinct religio-cultural segment of the Western Himalayan region. In this region, Buddhism has been a living religion of the major bulk of the population. This region has attracted attention of the modern explorers, researchers and scholars since the nineteenth century. They have contributed enormously on adventure, travel, religion and art of this region, mostly to evoke curiosity in the exotic culture of this region. Nevertheless, this area, left to the blissful oblivion, has remained almost an enigma of the regional history. What is historically available on this region is either the apocryphal account of the Buddhist movement since its introduction during the Second Epoch in the tenth century from Central Tibet of the cursory and peripheral references of this region in the historical accounts of the neighbouring kingdoms. The political and social history of this region has, thus, not only remained suppressed by and subservient to the history of Buddhism in Tibet, but is also infected with strong monastic bias. The present work is a result of the strenuous efforts of the author for many years. An attempt has been made to piece together all the available source material – literary, archaeological and traditional – to construct a cogent and well-reasoned account of the historical events in this Himalayan Shangri-la of Buddhism. Towards that end, the histories of the neighbouring kingdoms and powers, which influenced the course of history of this region, have also been correlated so that the historical events of this region are integrated into the wider socio-cultural, religious and political format of the entire Western Himalayan region. It is for the first time that an integrated socio-political and religious history of this region has been attempted.