The ritual of o?ering the guru mandala, i.e. o?ering a mandala of the Buddha, Dharma, and Sangha, to the guru, lies at the very heart of Newar Buddhism. Yagyaman Pati Bajracharya is a leading figure, perhaps the leading figure, in the contemporary revival of traditional Newar Buddhism, a religious tradition that goes back, in a direct line of descent, to the great monastic universities of northern India a millennium and more ago. This historical pedigree means that the rituals and practices of Newar Buddhism are unrecognized global treasures of intangible cultural and religious heritage. The translators and editors of this volume, Samuel M. Grimes and Alexander James O'Neill, present a faithful English rendering of Yagyaman's polyglot text. Drawing not only on a deep understanding of his own tradition but also on Indological scholarship, Yagyaman provides a detailed explanation of the text of the ritual. More than that, by way of introduction, he also dives deep into the historical meanings of the key terms 'guru' and 'mandala'. This book is therefore an indispensable guide for anyone seeking to grasp the essence and meaning of Newar Buddhism.