The present work discusses the nature and role of Buddhism in the history of Indian ideas. Beginning with a general survey of the history of researches on Buddhism, it makes a reassessment of the views on the origins of Buddhism put forward by eminent scholars and deals with the ideological background of Buddhism in which its key concepts as found in other sources have been traced, identified and documented. The traditional substrata of the Buddhist mythology have also been explored from the pre-Vedic, Vedic, Puranic, regional and tribal sources. The standpoints of the Jains, Vedantists, Mīmāmsakas and Nyāya-Vaiśesikas clearly suggest that Buddhism was viewed by its opponents as a thought-complex and not as a distinct religious system. The book also points out how factionalism arising out of personality clashes eventually led to doctrinal centrifugality. It concludes with the final transformation of Buddhism with reference to its basic character as the crucible for generating various ideas and practices. Substantial number of pages on Buddhist iconography appended at the end further enriches this path-breaking work.