One of 14 tinted lithographs by Brevet Major J R Turnbull, 13th Light Infantry, from 'Sketches of Delhi take during the Siege', published by T McLean, 1858. The Flagstaff Tower, a signal tower built in the 1820s, was situated on the Delhi Ridge. When the Indian Mutiny broke out the tower was a rallying point for Europeans fleeing the rebels. The Delhi Ridge was captured and fortified by the British in June 1857. By 14 September 1857 the British had about 9,000 men before Delhi. A third were British while the rest were Sikhs, Punjabis and Gurkhas. By 14 September 1857 the British had about 9,000 men before Delhi. A third were British while the rest were Sikhs, Punjabis and Gurkhas. The assault began when artillery breached the city walls and sappers blew in the Kashmir Gate. It took a week of vicious street fighting before Delhi was finally taken. The British and their Indian allies then ransacked the city in an orgy of looting and killing. Delhi's capture was key to British suppression of the Indian Mutiny (1857-1859).