Doctrine of lapse
The doctrine of lapse was an annexation policy applied by the British East India Company in India until 1859. According to the doctrine, any Indian princely state under the suzerainty of the British East India Company (the dominant imperial power in the subcontinent), as a vassal state under the British subsidiary system, it would have its princely status abolished (and therefore be annexed into British India) if the ruler was either "manifestly incompetent or died without a male heir". The latter supplanted the long-established right of an Indian sovereign without an heir to choose a successor. In addition, the British decided whether potential rulers were competent enough. The doctrine and its applications were widely regarded by many Indians as illegitimate.
The policy is most commonly associated with Lord Dalhousie, who was the Governor General of the East India Company in India between 1848 and 1856. However, it was articulated by the Court of Directors of the East India Company as early as 1847 and several smaller states had already been annexed under this doctrine before Dalhousie took over the post of Governor-General. Dalhousie used the policy most vigorously and extensively, though, so it is generally associated with him.
At the time of its adoption, the British East India Company had imperial administrative jurisdiction over wide regions of the subcontinent. The company took over the princely states of Satara (1848), Jaitpur and Sambalpur (1849), Nagpur and Jhansi (1854), Tore and Arcot (1855) and Udaipur (Chhattisgarh) under the terms of the doctrine of lapse. Oudh (1856) is widely believed to have been annexed under the Doctrine of Lapse. However it was annexed by Lord Dalhousie under the pretext of misgovernance. Mostly claiming that the ruler was not ruling properly, the Company added about four million pounds sterling to its annual revenue by virtue of this doctrine. Udaipur State, however, would have local rule reinstated by the British in 1860.
With the increasing power of the East India Company, discontent simmered among many sections of Indian society and the largely indigenous armed forces; these rallied behind the deposed dynasties during the Indian Rebellion of 1857, also known as the Sepoy Mutiny. Following the rebellion, in 1858, the new British Viceroy of India, whose rule replaced that of the British East India Company, renounced the doctrine.
The princely state of Kittur was taken over by the East India Company in 1824 by imposing a 'doctrine of lapse'. So it is debatable whether it was devised by Lord Dalhousie in 1848, though he arguably made it official by documenting it. Dalhousie's annexations and the doctrine of lapse had caused suspicion and uneasiness among most ruling princes in India.
Dalhousie applied the doctrine of lapse vigorously for annexing Indian princely states, but the policy was not solely his invention. The Court of Directors of the East India Company had articulated this early in 1834. As per this policy, the Company annexed Mandvi in 1839, Kolaba and Jalaun in 1840 and Surat in 1842.