Mahamudra or the Great Seal, refers to a Mahayana Buddhist system of meditation on nature of the mind and is undertaken for realizing Enlightenment. Taught by Buddha manifesting in the form of Vajradhara, its lineage was passed in India from Tilopa to Naropa to Marpa, and then in Tibet to Mi-la-ra-pa and Gam-po-pa, author of The Jewel Ornament of liberation. The specific lineage represented here is that of the Kar-ma Ka-gyu which passed from Gam-po-pa to the first Kar-ma-pa and then through successive Gurus until the present day. This text by the Ninth Kar-ma-pa is one of the most famous expositions of this meditational system. It covers both the preliminary practices as well as the actual Mahamudra meditations of mental quiescence (Samatha) and penetrative insight (vipasyana). Explaining the stages and paths as traveled in this system, it represents a complete path to Enlightenment. Accompanying the root text is a commentary given orally by Beru Khyentze Rinpoche, based on the teachings of his Guru, His Holiness the Sixteenth Kar-ma-pa. As a proper relation with a guru is essential for realizing Mahamudra, also included is the basic text on Guru-devotion by the first century B.C. Indian master Asvaghosa with an oral commentary by Geshe Ngawang Dhargyey. This work is published under the auspices of the Library of Tibetan Works and Archives in a programme to make available living teachings from the many tradition of Buddhism as preserved in Tibet.