Jhalkari Bai, the Rani of Jhansi's maid and confidante. Matadeen Hela, the man who provoked Mangal Pandey to action. These are just two of the names you're unlikely to read about in the history books – heroes of the 1857 Mutiny who have never been written about. Till now, as India’s Dalits rewrite their history to highlight their contribution to the country's first struggle for independence.