Population transfer or resettlement is the movement of a large group of people from one region to another, often a form of forced migration imposed by state policy or international authority and most frequently on the basis of ethnicity or religion but also due to economic development. Banishment or exile is a similar process, but is forcibly applied to individuals and groups.
Often the affected population is transferred by force to a distant region, perhaps not suited to their way of life, causing them substantial harm. In addition, the loss of all immovable property and, when rushed, the loss of substantial amounts of movable property, is implied. This transfer may be motivated by the more powerful party's desire to make other uses of the land in question or, less often, by disastrous environmental or economic conditions that require relocation.
In Europe, the last major population transfer was the deportation of 800,000, and displacement of 250,000 other ethnic Albanians, during the Kosovo war in 1999. The single largest population transfer in history was the flight and expulsion of Germans after World War II, which involved more than 12 million people. Moreover, some of the largest population transfers in Europe have been attributed to the ethnic policies of the Soviet Union under Joseph Stalin. The best-known recent example caused by economic development is that resulting from the construction of the Three Gorges Dam in China.
Population exchange is the transfer of two populations in opposite directions at about the same time. In theory at least, the exchange is non-forcible, but the reality of the effects of these exchanges has always been unequal, and at least one half of the so-called "exchange" has usually been forced by the stronger or richer participant. Such exchanges have taken place several times in the 20th century: two examples are the traumatic partition of India and Pakistan and the mass expulsion of Anatolian Greeks and Greek Muslims from Turkey and Greece, respectively, during their so-called Greek-Turkish population exchange, involving approximately 1.3 million Anatolian Greeks and 354,000 Greek Muslims, most of whom were forcibly made refugees and de jure denaturalized from their homelands.