Since 1947, Arunachal Pradesh was a part of the North East Frontier Agency and was later made a Union Territory. Arunachal Pradesh was made a full fledged state on 20th February, 1987.
16 : Tawang, West Kameng, East Kameng, Papumpare, Lower Subansiri, Upper Subansiri, East Siang, West Siang, Upper Siang, Dibang Valley, Lower Dibang Valley, Lohit, Changlang, Tirap, Kurung Kumey, Anjaw.
The McMahon Line separates it from the zone of control of the People's Republic of China to the north. Arunachal Pradesh is one of two main disputed regions between India and China, the other being Aksai Chin: the People's Republic of China does not recognize the state of Arunachal Pradesh, nor the McMahon Line. Instead, the PRC government refers to the region as occupied by India