Fifty years after the invasion and forced annexation to China, with the exile of many lamas from their land, terms such as 'tantra', 'lama' or 'mandala' have become common words. But what is Tibetan Buddhism? What are its origins and main doctrines? What is the difference between the various schools? How did it evolve and who were the most representative figures? In the book Powers outlines the Indian origins of the Vajrayana, focusing in particular on the figure of the historical Buddha, on the doctrines of Mahayana, the Indian school that spread in Tibet, and on the ideal of the bodhisattva. Again he examines the two key concepts of 'karma' and 'rebirth' and the Buddhist teaching of the dependent origination of all phenomena. It explains in detail the fundamental role played by meditation in Indian and Tibetan Buddhism and the difference between stabilizing and analytical meditation. The chapter "II tantra" enters the heart of Tibetan Buddhism, in which Tantric practices are considered the fastest and most effective path to Buddhahood. Powers examines in detail the four classes of tantra, initiation, preliminary practices, divinity yoga, mandala offering, guru yoga, and practices related to the moment of death and the bardo. The last chapter considers the similarities and differences of the four main lineages, Nyingma, Kagyu, Sakya and Geluk, and of the Rime, the 'non-sectarian movement'.