Siege of Delhi, Indian Mutiny, September 1857 (c1895). Siege of Delhi, Indian Mutiny, September 1857 (c1895). Engineers blowing up the Cashmere Gate so that British soldiers commanded by Colonel Campbell could pass into the city. The Indian Mutiny was an uprising against British rule in India which began in 1857. The mutiny had many underlying causes, but was sparked by the introduction of cartridges which were greased with animal fat. This outraged both Muslim and Hindu soldiers (sepoys), who made up the majority of the Indian army at the time. Although the mutiny was defeated in 1859, it led to the administration of India passing from the East India Company to the Crown. The capture of Delhi from the mutineers was vital to the British due to the city's symbolic importance as the seat of India's Mughal rulers.