Sorry, what I meant was the rulers of the Republic of China fled to Taiwan after 1949.
Former members of the UN: Republic of China:
Republic of China
The Republic of China (ROC) joined the UN as an
original member on 24 October 1945, and as set out by the United Nations Charter, Chapter V, Article 23, became one of the five permanent members of the United Nations Security Council. In 1949, as a result of the Chinese Civil War, the Kuomintang-led ROC government lost effective control of mainland China and relocated to the island of Taiwan, and the Communist Party-led government of the People's Republic of China (PRC), declared on 1 October 1949, took control of mainland China. The UN was notified on 18 November 1949 of the formation of the Central People's Government of the People's Republic of China; however, the Government of the Republic of China continued to represent China at the UN, despite the small size of the ROC's jurisdiction of Taiwan and a number of smaller islands compared to the PRC's jurisdiction of mainland China. As both governments claimed to be the sole legitimate representative of China, proposals to effect a change in the representation of China in the UN were discussed but rejected for the next two decades, as the ROC was still recognized as the sole legitimate representative of China by a majority of UN members.[citation needed] Both sides rejected compromise proposals to allow both states to participate in the UN, based on the One-China policy.
By the 1970s, a shift had occurred in international diplomatic circles and the PRC had gained the upper hand in international diplomatic relations and recognition count. On 25 October 1971, the 21st time the United Nations General Assembly debated on the PRC's admission into the UN, United Nations General Assembly Resolution 2758 was adopted, by which it recognized that "the representatives of the Government of the People's Republic of China are the only lawful representatives of China to the United Nations and that the People's Republic of China is one of the five permanent members of the Security Council," and decided "to restore all its rights to the People's Republic of China and to recognize the representatives of its Government as the only legitimate representatives of China to the United Nations, and to expel forthwith the representatives of Chiang Kai-shek from the place which they unlawfully occupy at the United Nations and in all the organizations related to it." This effectively transferred the seat of China in the UN, including its permanent seat on the Security Council, from the ROC to the PRC, and expelled the ROC from the UN. From the United Nations' perspective the "Republic of China" is not a former member. No UN member was expelled in 1971. Rather, the credentials of one Chinese delegation (from Taipei) were rejected and the credentials of another Chinese delegation (from Beijing) were accepted.
In addition to losing its seat in the UN, the UN Secretary-General concluded from the resolution that the General Assembly considered Taiwan to be a province of China. Consequently, the Secretary-General decided that it was not permitted for the ROC to become a party to treaties deposited with it