In 1854, French aeronaut Eugène Godard performed several manned balloon demonstrations at the wedding of Austrian Emperor Franz Joseph I. The Emperor was so impressed that he drafted an agreement with the Godard stating that in the event of a war, he would build balloons, organize balloonists companies, and perform observation ascents for the Austrian military. However, in 1859 the French went to war against the Austrians, and Godard's observation balloons were used instead by French forces, contributing to a victory for Napoleon III over Franz Joseph. Godard's aerial reconnaissance balloons were again employed by the French in 1870 during the Franco-Prussian War and the Siege of Paris.