organization established as the successor to the International Refugee Organization (IRO; 1946–52) by the United Nations (UN) General Assembly in 1951 to provide legal and political protection for refugees (refugee) until they could acquire nationality in new countries of residence. International refugee assistance was first provided by the League of Nations (Nations, League of) in 1921 under the leadership of Fridtjof Nansen (Nansen, Fridtjof), who served as the League's Commissioner for Refugees. In 1943 the United Nations Relief and Rehabilitation Administration, which was succeeded by the IRO in 1946, was established to assist people who had been displaced by World War II. A humanitarian and nonpolitical organization, the UNHCR was awarded the Nobel Prize for Peace in 1954 and 1981.

With its headquarters in Geneva, Switzerland, and branch offices in important countries of asylum, the UNHCR intervenes with various national governments in order to ensure such minimal rights as freedom from arbitrary expulsion, access to the courts, work and educational opportunities, and possession of identity and travel documents. The UNHCR initially focused its efforts on aiding the more than one million refugees and displaced persons in Europe after World War II. Since the 1960s the UNHCR's efforts have shifted to resettling refugees who are victims of war, political turmoil, or natural disasters in Africa and parts of Asia and Latin America. In addition to providing basic international legal protection for displaced persons, it works with other UN agencies—including the World Food Programme and the World Health Organization—nongovernmental organizations, and regional organizations to provide housing, food, and material assistance and aid in repatriation and resettlement. The High Commissioner, who reports annually to the General Assembly through the Economic and Social Council, has become a key public figure in efforts to rally international support for refugee programs.