On 26 January 1950, the Constitution of India was adopted formally and came into effect. Its preamble set out in brief the enlightened values it enshrined and hoped to engender. In a radical shift from mainstream constitutional history, this book establishes Dr B.R. Ambedkar's irrefutable authorship of the preamble by uncovering the intellectual origins of its six most central concepts-justice, liberty, equality, fraternity, dignity, and nation. Although Dr Ambedkar is universally regarded as the chief architect of the Constitution, the specifics of his role as chairman of the Drafting Committee are not widely discussed. Totally neglected is his almost single-handed authorship of the Constitution's Preamble, which is frequently and mistakenly attributed to B.N. Rau rather than to Ambedkar. This book establishes how and why the Preamble to the Constitution of India is essentially an Ambedkarite preamble. It is clear that its central concepts have their provenance in Ambedkar's writings and speeches. Through six eponymous chapters, this book unfolds the story of the six constitutional concepts. In doing so, it spotlights fundamental facts about modern Indian history, as well as Ambedkar's revolutionary political thought, hitherto ignored in conventional accounts.