The Instrument of Accession was a legal document first introduced by the Government of India Act 1935 and used in 1947 to enable each of the rulers of the princely states under British paramountcy to join one of the new dominions of India or Pakistan created by the Partition of British India.
The instruments of accession executed by the rulers, provided for the accession of states to the Dominion of India (or Pakistan) on three subjects, namely, defence, external affairs and communications.
The Indo-Pakistani war of 1947–1948, also known as the first Kashmir war, was a war fought between India and Pakistan over the princely state of Jammu and Kashmir from 1947 to 1948. It was the first of four Indo-Pakistani wars between the two newly independent nations. Pakistan precipitated the war a few weeks after its independence by launching tribal lashkar (militias) from Waziristan, in an effort to capture Kashmir and to preempt the possibility of its ruler joining India.
Hari Singh, the Maharaja of Jammu and Kashmir, was facing an uprising by his Muslim subjects in Poonch, and lost control in portions of the western districts. On 22 October 1947, Pakistan's Pashtun tribal militias crossed the border of the state. These local tribal militias and irregular Pakistani forces moved to take the capital city of Srinagar, but upon reaching Baramulla, they took to plunder and stalled. Maharaja Hari Singh made a plea to India for assistance, and help was offered, but it was subject to his signing of an Instrument of Accession to India.
Amb (Urdu, Hindko: امب) was a princely state within the Hazara Tribal Agency of North-West Frontier Province, British India, ruled by the Tanoli tribe. Together with the neighbouring estate of Phulra, the tract was known as "Feudal Tanawal". Its total area was 203 sq mi (530 km) while population was 48,656 in 1951. The Nawab of Amb Muhammad Farid Khan acceded to Pakistan after the independence of Pakistan in 1947. Today Amb is a part of Mansehra District of Hazara Division.
Amb came under the British suzerainty after the Second Anglo-Sikh War, with Mir Jehandad Khan providing much assistance to the East India Company against the Sikhs. The Amb Nawabs also provided military services to the British Empire in the Second Anglo-Afghan War. At the end of December 1947, the Nawab of Amb acceded to Pakistan while retaining internal self-government. Amb continued as a princely state of Pakistan until 1969, when it was incorporated into the North West Frontier Province (now Khyber Pakhtunkhwa).
Dir was a princely state in a subsidiary alliance with the British Raj, located within the North-West Frontier Province. Following the Partition of British India, Dir remained independent and unaligned until February 1948, when the Dominion of Pakistan accepted its accession.
The princely state ceased to exist as a distinct political entity in 1969, when it was fully incorporated into Pakistan. The territory it once covered is today located in the Pakistani province of Khyber Pakhtunkhwa, forming two northern and southern districts called Upper Dir and Lower Dir, respectively.
State of Swat (Urdu: رياست سوات) was a state established in 1849 by the Muslim saint Saidu Baba, also known as Akhund of Swat, and was ruled by Walis of Swat. It was recognized as a princely state in alliance with the British Raj between 1918 and 1947, after which the Akhwand acceded to the newly independent state of Pakistan. Swat continued to exist as an autonomous region until it was dissolved in 1969, and incorporated into Khyber Pakhtunkhwa province (formerly North-West Frontier Province). The area it covered is now divided among the present-day districts of Swat, Buner, Kohistan and Shangla.
The Annexation of Hyderabad (code-named Operation Polo) was a military operation launched in September 1948 that resulted in the annexation of the princely state of Hyderabad by India, which was dubbed a "police action".
At the time of partition of India in 1947, the princely states of India, who in principle had self-government within their territories, were subject to subsidiary alliances with the British, which gave control of external relations to the British. With the Indian Independence Act 1947, the British abandoned all such alliances, leaving the states with the option of opting for full independence. However, by 1948 almost all had acceded to either India or Pakistan. One major exception was that of the wealthiest and most powerful principality, Hyderabad, where the Nizam, Mir Osman Ali Khan, Asaf Jah VII, a Muslim ruler who presided over a largely Hindu population, chose independence and hoped to maintain this with an irregular army. The Nizam was also beset by the Telangana rebellion, which he was unable to crush.