In 1913 Tibet declared independence from China.

In October 1950 China invaded Tibet.

In May 1951, Tibet affirmed China’s sovereignty and established an autonomous administration led by Dalai Lama.

In 1959 the Dalai Lama fled to northern India and established the Central Tibetan Administration.

The Tibet Autonomous Region within China was officially established in 1965.[1]
Source: History of Tibet (1950–present)