The Franco-Prussian War was fought between France and Prussia with a coalition of German states from July 15, 1870 to February 1, 1871. Prussian leadership of the German states had been confirmed after Prussia's defeat of Austria in the Seven Weeks' War in 1866. This threatened France's position as the dominant power in Europe. Prince Leopold's candidacy for the Spanish throne was one of the immediate causes of the Franco-Prussian War. It was Otto von Bismarck, the Prussian chancellor, and the de facto ruler of Spain, Juan Prim, who persuaded a very reluctant Leopold to accept the Spanish throne in June 1870. This decision was alarming for France , the possible combination of Prussia and Spain being directed against it. was threatening. Leopold's candidacy was withdrawn under French diplomatic pressure. The French ambassador asked them to promise that Leopold would never again be allowed to be a candidate for the Spanish throne, which King William I politely refused. A telegram describing this incident was sent to Bismarck. In which he edited the original description and on July 14 he ...