The end of the Franco Prussian War resulted in the defeat of France and subsequent loss of its territories of Alsace and Lorraine to the Germans. This ended the balance of power that had existed in Europe since the Congress of Vienna in 1915.
France was determined to regain its lost territories. This caused Germany to form alliances with the Austro Hungarian Empire and reinforce its military. This period was the prelude to the First World War in 1914.