South Tibet in the context of Mainling County

The Line of Actual Control (LAC), in the context of the Sino-Indian border dispute, is a notional demarcation linethat separates Indian-controlled territory from Chinese-controlled territory on their mutual border. The concept was introduced by Chinese premier Zhou Enlai in a 1959 letter to Jawaharlal Nehru as the "line up to which each side exercises actual control", but rejected by Nehru as being incoherent. Subsequently, the term came to refer to the line formed after the 1962 Sino-Indian War.

The LAC is different from the borders claimed by each country in the Sino-Indian border dispute. The Indian claims include the entire Aksai Chin region and the Chinese claims include Arunachal Pradesh/Zangnan. These claims are not included in the concept of "actual control".

Arunachal Pradesh (/ərʊˌnɑːtʃəl prəˈdeɪʃ/; lit. 'Dawn-Lit Mountain Province') is a state in northeast India. It was known as the North-East Frontier Agency until 1972, after which it became a union territory under the name Arunachal Pradesh. It became a state on 20 February 1987. Itanagar is its capital and largest town.

It shares international borders with Bhutan in the west, Myanmar in the east, and a disputed 1,129 km border with China's Tibet Autonomous Region in the north at the McMahon Line. Arunachal Pradesh is claimed in its entirety by China as South Tibet as part of the Tibet Autonomous Region; China occupied some regions of Arunachal Pradesh in 1962 but later withdrew its forces.