The period of 1864/1865-1870 represents the final stage of the unification of Germany, during which Prussia adopted a resolute approach and in two quick wars succeeded in eliminating its enemies - Austria and France. The aim of the diploma thesis is to present and critically analyse the Prussian foreign policy based on the study of sources and relevant literature. The author assesses factors which influenced the Prussian prime minister and the representatives of the European powers in their decisions. He also asks the question whether Bismarck merely adapted to the circumstances which inevitably led to the war with Austria or whether he himself contributed to their creation and speeded up the whole process. The most attention is then paid to France which was the greatest opponent of the unification of Germany of all powers. The study looks into the methods and steps which enabled Prussia to prevent the great European powers from getting involved into its conflict with Vienna and Paris. Moreover, it points out the challenges of the research on circumstances which led to the outbreak of the Franco-Prussian War. Key words Prussia, Great Powers, German Confederation, Unification of Germany, Austrian Empire, Austria-Hungary, foreign policy, Austro-Prussian War, Franco-Prussian War, Napoleon III