What is now Arunachal Pradesh was established as the North-East Frontier Agency (NEFA) in 1954 and Sino-Indian relations were cordial until 1960. Resurgence of the border disagreement was a factor leading to the Sino-Indian War in 1962, during which China captured most of Arunachal Pradesh. However, China soon declared victory, withdrew back to the McMahon Line and returned Indian prisoners of war in 1963.[17][18][19]