After a four years of civil war from 1946 to 1949, the Chinese Nationalist Party (KMT), which previously controlled Mainland China as well as Taiwan, lost control of the former, which in turn came to be occupied by the Chinese Communist Party under the People's Republic of China.
As defeat on the Mainland became imminent, the nationalists relocated their forces, capital and equipment, as well as most national treasures to Taiwan. A total of over a million mainlanders (Chinese: 外省人; Pinyin: wàishěngrén) immigrated to the island with an existing population of roughly 6 million islanders (Chinese: 本省人; Pinyin: běnshěngrén).
The nationalists hadn't accepted defeat and officially maintained their claims to Mainland China as well as Mongolia until the 1990s. Their original plan was to reassemble their troops and recapture the Mainland to liberate it from communism. Taiwan was to serve as a temporary holdout and a springboard for the invasion of the Mainland. For this reason, investment in the long-term welfare of the people on Taiwan were few and far between in the years following the Retrocession, and advocating for Taiwan independence was considered to go against the KMT's "one-China" principle and was fiercely suppressed.
Since all provinces of the Republic of China bar Taiwan were occupied by the Communists, national level elections, as well as all elections in municipalities not on Taiwan were suspended, and the seats of representatives of these regions in the Legislative Yuan were not contested in elections.
