The area of Naga Hills was a part of Assam under the British Colonial Rule, the Britishers adopted a non-interference policy into the Naga affairs, which soon resulted in harmony between them and the Nagas. Naga territories were excluded from the direct purview of the British Rule which was the reason why Nagas were loyal to the British Government, and simultaneously the Naga people developed a separatist approach post-independence. There were two forces at work, Destructive and Constructive, the former was in favour of seceding the Naga Hills from the Union of India and the latter wanted to solve the problem peacefully. Soon after independence, the Naga National Council insisted on the formation of an interim government giving them full powers of the Legislature, Executive & Judiciary over the territory of Naga Hills for 10 years. The Government of free India however, never wanted such cessation of the Indian territory which caused peaceful leaders to adopt violent measures to meet their ends causing bloodshed. The Government of India led by Jawahar Lal Nehru, to show a great matter of concern for the Naga people, came to an agreement with the leaders of Nagas Convention which declared the Naga Hills–Tuensang Area (Nagaland) as the 16th Constituent State of the Union of India. This ensured the protection of the customary laws and religious beliefs of the Nagas.
The terms of agreement (which were later inserted in the Indian Constitution as Article 371A) were such-
There were various factors responsible for the emergence of Nagaland. The culture, customs, religion, and ethics of Nagas varied from those in Assam. Naga people were not sure of their protection until they had a separate identity and status. The neighbouring countries encouraged hostile elements to disturb the peace and relations of the Government of India and the north-eastern region reason being the covetous nature. Also, the pre-independence British policy made their region isolated from the rest of India. The main reason to bring such autonomy was to cool down their resentment against the people of India. Shilu Ao, the Chief Minister welcomed this help for building up a new state by the Government of India.
“Thus, the creation of Nagaland state as a constituent of the Indian Union in 1963was the culmination of political and democratic processes which had been set in motion by the first Naga people’s convention in 1957.”