On 10 May 1857, the most serious threat to British supremacy in India appeared at Meerut. After months of increasing tension, sepoys of the 3rd Light Cavalry along with the 11th and 20th Native Infantry pointedly refused to use the new cartridges supplied to them. ‘The company Raj is over forever,’ declared the men to their British officers as they burned their cantonments, and the cry of ‘Dilli chalo‘ was heard as they marched to the old Mughal capital. There the Mughal Empire was declared resurrected and the Emperor Bahadur Shah Zafar, an ageing pensioner of the British government, affirmed as the ruler of all Hindustan once again. With the mutiny spreading rapidly, it became imperative for the British to recapture Delhi as the success or failure of the uprising hinged entirely on the possession of the city. It would take three months of bloody fighting for the British Delhi Field Force to defeat the rebel sepoys and recapture the city, a period in which it became unclear quite who besieged whom.
In The Siege of Delhi, historian Amarpal Singh comprehensively narrates the story from the uprising at Meerut to the climactic capture and sack of Delhi.