The Revolt of 1857 which is called 'Sepoy Mutiny', 'Great Revolt' and the 'First War of Indian Independence is the watershed in the history of pre-independent and early colonial India. A major cause was the unrest of the sepoys in the army of the British. The action of Mangal Pandey, a sepoy of Barrackpore near Calcutta on 29 March, 1857 led to the mutiny of sepoys in the beginning which precipitated the revolt of the people. The suspicion that the greased cartridge which was used in Enfield rifles was filled with the fat of cow and pig made the sepoys to openly rebel by killing a British officer.