Written in India in the early eighth century AD, Santideva´s Bodhicaryavatara became one of the most popular accounts of the Buddhist´s spiritual path. The Bodhicaryavatara takes as its subject the profound desire to become a Buddha and save all beings from suffering. The person who enacts such a desire is a Bodhisattva. Santideva not only sets out what the Bodhisattva must do and become, he also invokes the intense feelings of aspiration which underlie such a commitment, using language which has inspired Buddhists in their religious life from his time to the present. Important as a manual of training among Mahayana Buddhists, especially in the Tibetan Buddhist tradition, the Bodhicaryavatara continues to be used as the basis for teaching by modern Buddhist teachers. This is a new translation from the original language, with detailed annotations explaining allusions and technical references. The Introduction sets Santideva´s work in context, and for the first time explain its structure.