History of the administrative divisions of China (1949–present)

The Chinese Communist Party (CCP) initially held scattered fragments of mainland China at the start of the Chinese Civil War. By the establishment of the People's Republic of China in October 1949, the CCP controlled the majority of mainland China, forcing the Republic of China government to retreat to Taiwan.

Source: Wikipedia — History of the administrative divisions of China (1949–present) (CC BY-SA 4.0)