Accession Day is observed on 26 October every year, it is a public holiday in the Union Territory of Jammu and Kashmir. When Maharaja Hari Singh signed off the Instrument of Accession, they agreed that Jammu and Kashmir would become a part of india.
After Independence, the three rulers had not merged their union territories. These were: the Nawab of Junagadh, the Nizam of Hyderabad, and Maharaja Hari Singh of Kashmir.
On 16 March 1846, Kashmir declared as a princely state after British acquired it. They then sold it to Gulab Singh, the ruler of Jammu. Hari Singh was the great-grandson of Gulab Singh.
In the week after 15 August 1947, Hari singh gave no indication to giving up his state. Pakistan sends troops to acquire Kashmir but by then Indian forces had taken control of nearly two thirds of the state. Gilgit and Baltistan territories were secured by Pakistani troops. Fighting between Indian troops, and the tribesmen and Pakistani troops continued for more than a year after the accession, in what is generally known as the first India-Pakistan war.
Finally, a United Nations ceasefire was arranged at the end of 1948. After long negotiations, the cease-fire was agreed to by both countries, and came into effect. The terms of the cease-fire, laid out in a United Nations resolution of 13 August 1948, were adopted by the UN on 5 January 1949.
“The Accession of the State of Jammu and Kashmir to India, signed by the Maharaja on 26 October 1947, was completely valid under the Government of India Act 1935 and international law and was total and irrevocable. The Accession was also supported by the largest political party in the State, the National Conference. In the Indian Independence Act, there was no provision for any conditional accession”.
The “Accession Day” is observed as “Black Day” by separatist Kashmiri leaders like Syed Ali Shah Geelani and followers of All Parties Hurriyat Conference in protest of alleged human rights violations by the India’s “occupation” of Jammu and Kashmir.