Countless Buddhist teachers and practitioners have appeared over the centuries in the snowy land of Tibet. None have made a deeper impact on the combined religious, artistic, and technological his- tory of the country than the great adept (mah›siddha, grub chen) Tangtong Gyalpo, “King of the Empty Plain” (Thang stong rgyal po, 1361?−1485). This heroic figure became legendary because of his contributions to the mystical traditions, his exceptionally long life, and his innovative achieve- ments in the fields of art, architecture, and metallurgy. Tangtong’s life and teachings are intertwined with divine madness, visionary revelation, demon exorcism, the quest for immortality, the relationship of human beings with their environment, and the process of ultimate enlightenment.