The Nispannayogavali (NSP) has been a major source for the identification and symbolism of the mandalas for the last sixty years. It was written by Abhayakaragupta who headed the great Vikramasila monastery. Born as the son of the King of Singala, he was ordained in the Sarvastivada tradition, and studied the Tantras at Nalanda and Vikramasila. Vajrayogini appeared to him and said: write an extensive ritual of mandalas. He authored a trilogy of texts on the mandalas. Among them the NSP elaborates the emanation (utpanna-krama) of the deities of 26 mandalas, details their attributes, mantras and bijas for meditation. It specifies the sanctified space in which a mandala is visualised, beginning with the complete sanctified area (vajra-panjara) to the vajra-rampart, protective circle, Mount Sumeru, the trigon and the pavilion in which the mandala emanates. The complete Sanskrit text has been corrected with the help of a Nepalese manuscript of 1200 AC, compared with the Tibetan text and translated into English for the first time. The Sanskrit text, its meticulous Tibetan rendering and English translation fill a long-felt need ever since B. Bhattacharyya's casual edition of the Sanskrit version appeared in 1949. It is a must for the history of Buddhist art, the living tradition of meditation on mandalas, and philosophy of Esoteric Buddhism. The Sanskrit text in Devanagari is followed by the Tibetan version in Tibetan script to facilitate a comparative study. The English translation grants access to the wider circle of art historians.