Tibet
With the invasion of Tibet in 1950 and the subsequent Seventeen Point Agreement, the PRC asserted control over Tibet.
Tibet had been under Chinese Imperial control in the past, but had been independent since 1912
Seventeen Point Agreement
Also called the Agreement of the Central People's Government and the Local Government of Tibet on Measures for the Peaceful Liberation of Tibet
the document by which the delegates of the 14th Dalai Lama reached an agreement with the government of the newly-established PRC on affirming Chinese sovereignty over Tibet.