The causes of the Franco-Prussian War are strongly rooted in the events surrounding the gradual march toward the unification of the German states under Otto von Bismarck. In the midst of the Austro-Prussian War of 1866, the Empress Eugénie, Foreign Minister Drouyn de Lhuys and War Minister Jacques Louis Randon, worried that a Prussian victory might jeopardize France's status as the dominant power in Europe, gained after the Franco-Austrian War of 1859, unsuccessfully urged Napoleon to implement an armed mediation which would consist in a mobilization and the massing of troops at France's eastern borders while the bulk of the Prussian armies were still engaged in Bohemia, as a warning that no territorial changes could be effected in Germany without consulting France. As a result of Prussia's annexation of several German states which had sided with Austria during the war and the formation of the North German Confederation under Prussia's aegis, French public opinion stiffened and now demanded more firmness as well as territorial compensations. As a result, Napoleon demanded from Prussia a return to the French borders of 1814, with the annexation of Luxembourg, most of Saarland, and the Bavarian Palatinate. Bismarck flatly refused what he disdainfully termed France's "politique des pourboires". He then communicated Napoleon's written territorial demands to Bavaria and the other southern German states of Württemberg, Baden and Hesse-Darmstadt, which hastened the conclusion of defensive military alliances with these states. France had been strongly opposed to any further alliance of German states, which would have significantly strengthened Prussia militarily.