The history of mail and postage stamps of Bahrain, an island state on the archipelago of the same name in the Persian Gulf in South-West Asia and the smallest Arab state, is conventionally divided into the period of its stay under the protectorate of Great Britain (1861-1971) and the period of the independent Kingdom of Bahrain (from August 14, 1971 of the year). Before issuing its own stamps in 1960, Bahrain used British India postage stamps without overprints (until 1933), then with overprints (1933-1947), and British postage stamps with overprints (1948-1960). Bahrain has been a member of the Universal Postal Union since 1973. Since May 1, 1986, Bahrain has been a member of the Arab Postal Union. The kingdom also co-founded the Gulf Postal Organization.