Governments in exile frequently occur during wartime occupation. For example, during the German expansion of the Second World War, numerous European governments and monarchs were forced to seek refuge in England, rather than face certain destruction at the hands of the Nazis.
Currently, there are few governments in exile, and those that exist are not widely recognized. Examples are the administration of Belarus exiled since 1920 and currently led by Ivonka Survilla in Canada, or the government of the Dalai Lama in India, claiming to be the legitimate leaders of the Chinese-occupied nation of Tibet.
See also: Governments in exile (WWII)