The Sino-Indian War, also known as the Sino-Indian Border Conflict, is a war between People's Republic of China and India.

The initial cause of the conflict is a disputed region of the Himalayan border in Arunachal Pradesh, known in China as South Tibet.

Fighting begins on 20 October 1962 between the People's Liberation Army and the Military of India.

The first heavy engagement of the war is a Chinese attack on an Indian patrol north of the McMahon Line.

The conflict eventually widens to include the region of Aksai Chin which the PRC regards as a strategic link, via the China National Highway route G219, between the Chinese-administered territories of Tibet and Xinjiang.

The war ends when the Chinese capture both disputed areas and unilaterally declare a ceasefire on 20 November 1962, which goes into effect at midnight.The Sino-Indian War is notable for the harsh conditions under which much of the fighting takes place, entailling large-scale combat at altitudes of over 4250 meters (14,000 feet).

This presents numerous logistical problems for both sides.The aftermath of the war sees sweeping changes in the Indian military to prepare it for similar conflicts in the future, and places pressure on Indian prime minister Jawaharlal Nehru, who is seen as responsible for failing to anticipate the Chinese invasion.