The starting point of this thesis is the mass conversion to Buddhism, in Nagpur in October 1956. The people who converted were all untouchables, and most of them were Maharashtrian Mahars, the caste to which Dr. Bhimrao Ramji Ambedkar (1891-1956) belonged. Ambedkar was the undisputed leader of the conversion movement, and it was due him his followers chose Buddhism. In 1935, he said he would leave Hinduism. I try to understand how Ambedkar provided legitimacy and support for the conversion to Buddhism, through his understanding of the Buddhist tradition and of Indian (religious) history in general. Ambedkar s level of education was impressive by all standards, and he was a prolific writer on a wide array of subject; the thesis built on his works, as well as on secondary literature. The second chapter gives a sketch of Ambedkar s life, and the historical context in which he lived. Here I will try to come to terms with great impact he had on his followers: the almost godlike status conferred upon him. Mohandas K. Gandhi takes a prominent place in this section, as well as elsewhere in the thesis: he was the main antagonist in Ambedkar s life and works. In the third chapter, I deal with the inevitable subjects of caste and untouchability: the main reason why the untouchables converted was to escape the Hindu caste system. The Hindu caste system is described using the concepts fragmentation graded inequality; Ambedkar s ingenious theory of how the untouchables were originally Buddhists is also treated. In the fourth chapter, I treat the matter of religion in general understood as basic values institutionalised in society as well as its Indian relatives dhamma (Pali) and dharma (Sanskrit). Those concepts were given an unusual meaning by him: dharma is hierarchical and particularistic, and is represented by Hinduism and Brahmanism, while dhamma is egalitarian and universal, and is represented by Buddhism. Ambedkar uses this dichotomy to describe the two main forces opposing each other in Indian history and society. In the fifth chapter, I present Ambedkar s view of the Hindu tradition to him defined by caste mostly through his readings of adversary texts , the Bhagavadgita in particular. In chapter six, I consider his radical reinterpretation of Buddhism as put forward in his main work The Buddha and his dhamma. I question whether Ambedkarite Buddhism (or Navayana) is authentic as he claimed it to be and what strategic concerns were behind his modernist interpretation the Buddhist tradition, inspired by the western Enlightenment project. Ambedkar aimed to provide the untouchables with a religion that would be suitable for their political and social emancipation, as well as providing a civil religion of universal moral values for Indian society. Throughout the thesis a consistent view of Indian (religious) history occasionally comes to the surface; this is the subject of the seventh chapter.