The abolition of Prussia occurred on 25 February 1947 by decree of the Allied Control Council, the governing authority of post-World War II occupied Germany and Austria. The decision was grounded in the view that Prussia had long embodied the most reactionary and militaristic elements within German political life. As the engine of German militarism and a key promoter of authoritarianism and expansionist policies, Prussia was seen as fundamentally incompatible with efforts to rebuild Germany as a peaceful and democratic state, and its dominance in German affairs had contributed directly to the wars of aggression that devastated Europe. By dismantling Prussia, the Allies aimed to eradicate the institutional structures most responsible for German aggression. This abolition referred strictly to the political entity of Prussia, not to the expulsion of ethnic Germans from East Prussia between 1945 and 1950.