In Tibetan Buddhism, Mahamudra represents a perfected level of meditative realization: it is the inseparable union of wisdom and compassion, of emptiness and skillful means. These eighty-four masters, some historical, some archetypal, accomplished this practice in India where they lived between the eighth and twelfth centuries. Leading unconventional lives, the siddhas include some of the greatest Buddhist teachers; Tilopa, Naropa, and Marpa among...