1 May 1950, the Island of Hainan was taken under full control by the PLA.[2] 19 May 1950, the largest archipelago of China - Zhoushan, was taken under full control of PLA.[3] 23 May 1951, the area of Tibet Autonomous Region was claimed by the People's Republic of China. 3 September 1954, The People's Republic of China annexed the Yijiangshan Islands and Dachen Islands from the Republic of China during the First Taiwan Strait Crisis (Battle of Yijiangshan) even as the U.S. Seventh Fleet was patrolling nearby.[4]