The multiplicity of small German states achieved real unity only with the rise of Prussia and the formation of the German Empire in the mid 19th century. After being defeated in the First World War, Germany was taken over in the 1930s by the Nazi dictatorship, which led to a policy of expansionism and eventually to complete defeat in the Second World War. Germany was occupied for a time by the victorious Allies and was partitioned. The western part (including West Berlin), which was occupied by the US, Britain, and France, became the Federal Republic of Germany or West Germany, with its capital at Bonn. The eastern part, occupied by the Soviet Union, became the German Democratic Republic or East Germany, with its capital in East Berlin. West Germany emerged as a major European industrial power and was a founder member of the EEC while the East remained under Soviet domination. After the general collapse of communism in eastern Europe, East and West Germany reunited on 3 October 1990