The Partition of Indian Sub-Continent and beginning of dispute.

In 1947, British rule in India ended with the creation of two new nations: the Union of India and the Dominion of Pakistan, while British suzerainty over the 562 Indian princely states ended. According to the Indian Independence Act 1947, "the suzerainty of His Majesty over the Indian States lapses, and with it, all treaties and agreements in force at the date of the passing of this Act between His Majesty and the rulers of Indian States",so the states were left to choose whether to join India or Pakistan or to remain independent. Jammu and Kashmir, the largest of the princely states, had a predominantly Muslim population, while having a Hindu ruler (Maharaja Hari Singh.) On partition Pakistan expected Kashmir to be annexed to it.In October 1947, Muslim revolutionaries in western Kashmir and Pakistani tribals from Dir entered Kashmir, intending to liberate it from Dogra rule. Unable to withstand the invasion, the Maharaja signed the Instrument of Accession on 25 October 1947 that was accepted by the government of India on 27 October 1947.

Maharaja of Kashmir Hari Singh at the time of Partition in 1947 

File Picture of  Viceroy Lord Louis Mountbatten, 1st Earl Mountbatten of Burma