Rebellion broke out when a soldier called Mangal Pandey attacked a British sergeant and wounded an adjutant while his regiment was in Barrackpore. General Hearsey ordered another Indian soldier to arrest Mangal Pandey but he refused. Later the British arrested Mangal Pandey and the other Indian soldier. The British killed both by hanging them because what they had done was thought to be treachery. All other soldiers of that regiment lost their places in the army. On May 10th 1857, cavalry troops while doing parade at Meerut broke ranks. They freed the soldiers of the 3rd regiment, and they moved towards Delhi. Soon many Indians of north India joined these soldiers. They entered the Delhi Fort where Bahadur Shah II, the Mughal Emperor, lived, and asked him to become leader of the rebellion. He agreed unwillingly. Very soon the revolt spread throughout north India. Important Indian leaders of royal families joined the rebellion, and started fighting the British at several places. They included: Ahmed Ullah, an advisor of the ex-King of Oudh; Nana Saheb, his nephew Rao Saheb, and his retainers, Tantia Tope and Rani Lakshmibai; the Rani of Jhansi; Kunwar Singh; the Rajput chief of Jagadishpur in Bihar; and Firuz Saha, a relative of the Mughal Emperor, Bahadur Shah.