The states of Pakistan and India were created by a process called Partition upon the withdrawel of the British from the South Asian continent. As South Asian Muslims demanded their own state the British devised the plan to separate the Muslim population from the Hindu population. Any area predominantly inhabited by Muslims would become Pakistan and any area predominantly inhabited by Hindus would become India. Hindus living in areas that were assigned to Pakistan often chose to resettle in India and Muslims living in areas that were assigned to India often chose to resettle in Pakistan. The result was a massive population transfer.
The Partition plan, however, did not provide any solutions for other major ethnic groups, like the Sikhs, or for any of the so-called Princely States, like Kashmir, which was predominantly populated by Muslims but ruled by a Hindu Maharadja. Tensions arose as to whether the ruling prince or the population should decide over the future of Kashmir. In 1947 a tribal rebellion breaks out over demands for a referendum. Pakistan aided those forces and soon the capital Srinagar was surrounded by insurgents and the Maharaja’s royal forces were defeated. The Maharaja turned to India for help. India was willing to help under the condition that Kashmir agrees to accession to India. The insurgency was topped but Kashmir was de facto divided along the various factious parties – with some parts being under India’s control and others under Pakistani rule.
Currently, India is redefining its governing relationship with Kashmir.