The erosion of British hegemony after the Franco-Prussian War, in which a coalition of German states led by Prussia defeated France, was occasioned by changes in the European and world economies and in the continental balance of power following the breakdown of the Concert of Europe, established by the Congress of Vienna. The establishment of nation-states in Germany and Italy resolved territorial issues that had kept potential rivals embroiled in internal affairs at the heart of Europe to Britain's advantage. The years from 1871 to 1914 would be marked by an extremely unstable peace. France's determination to recover Alsace-Lorraine, annexed by Germany as a result of the Franco-Prussian War, and Germany's mounting imperialist ambitions would keep the two nations constantly poised for conflict.