Residencies of British India not maintain military forces other than for internal policing or else form diplomatic alliances with other States. The Residents attempted to modernize these Native States through promotion of European notions of progressive government. The first Native States to enter such subsidiary alliances included Arcot, Oudh and Hyderabad. Before the Rebellion of 1857, the role of the British Resident in Delhi was more important than that of other Residents, because of the tension that existed between the declining Mughal Empire and the emerging power of the East India Company. After the establishment of Crown rule of British India in 1858, the
Colony of Aden was separated from British India to become a Crown Colony, a status that it retained until 1963. It consisted of the port city of Aden and its immediate surroundings (an area of 192 km², 75 sq. miles). The Aden Settlement, and later Aden Colony, also included the outlying islands of Kamaran ("de facto"), Perim and Kuria Muria (see map). Prior to 1937, Aden had been governed as part of British India (originally as the Aden Settlement under the Bombay Presidency, and then as a Chief Commissioner's province). Under the Government of India Act 1935 the territory was detached from British