Under League of Nations supervision in 1923, more than 1 million Greek residents of Asia Minor were repatriated, and some 800,000 Turks left Greece. During the German occupation (1941–44) and the civil war (1944–49), there was a general movement of people from the islands, the Peloponnesus, and the northern border regions into the urban areas, especially the Athens metropolitan area, including Piraiévs. Between 1955 and 1971 about 1,500,000 peasants left their farms—about 600,000 going to the cities, the rest abroad. According to the 1981 census, 813,490 Greeks had migrated since 1975 to urban areas, and 165,770 had moved to rural areas. The growth rate of the Athens, Thessaloniki, Pátrai, Iráklion, and Vólos metropolitan areas during 1971–81 far exceeded the population growth rate for the nation as a whole.
Many Greeks leave the country for economic reasons. In the years after World War II, the number of annual emigrants has varied from a high of 117,167 (in 1965) to a low of 20,330 (in 1975). The net outflow of Greek workers during the 1960s was 450,000; during the 1970s, however, there was a net inflow of 300,000. This mainly reflected declining need for foreign labor in western Europe.
In 1974, when the Greek military government collapsed, about 60,000 political refugees were living overseas; by the beginning of 1983, about half had been repatriated, the remainder being, for the most part, Communists who had fled to Soviet-bloc countries after the civil war of 1944–49.
In 1998, Greece received 2,953 applications for asylum, as compared to 4,367 in 1997. Most of them were from Iraq, Iran, and Turkey. Of those submitted in 1998, 10.6% were recognized as refugees or provided humanitarian protection. In 1999, the net migration rate was 4.04 migrants per 1,000 population.