Europeans came to the area that is now Zambia in small numbers during the first four decades of the twentieth century primarily as missionaries, administrators, farmers, or employees of the copper or lead and zinc mines. The most extensive period of European immigration, however, was the decade and a half following World War II. In 1946 there were 22,000 Europeans in the country, while in 1962 the European population reached a peak of 77,000. The overwhelming majority of Europeans came from South Africa, the Rhodesias (Zambia was then Northern Rhodesia), or Britain— in that order of frequency. Most of those born in the Rhodesias had British and/or South African ancestry. In the immediate preindependence period slightly more than a third of the Europeans were citizens of the Federation of Rhodesia and Nyasaland, into which Northern Rhodesia was incorporated from 1953 to 1963; most of the rest were approximately evenly divided between British and South African citizenship.