of the Untouchables (the lowest group in the caste system). He led the agitation for their constitutional rights in the 1930s and when Mahatma Gandhi went on a fast against the provision of separate electorates for the Untouchables, agreed to the Poona Pact (1934) providing reserved seats for them in the legislatures. As the leader and founder of the Scheduled Castes Federation, he opposed the Indian National Congress, but joined that party after independence. As a leading constitutional lawyer, he played a major role in formulating and drafting the Indian constitution.