For 225 years, defending France has been one of École Polytechnique's fundamental missions. Ever since its creation in 1794, its role has been to train civil and military engineers. This aspect was accentuated when Napoléon decided to militarize the School in 1804. The students' first military exploits came in 1814 when they defended the Paris city gates at the Barrière du Trône against the advancing European coalition forces. In 1830, the students were hostile to Charles X and supported the Revolution, taking an active part in the fighting on the Three Glorious Days of 28, 29 and 30 July 1830. It was on this occasion that a student named Vaneau was killed. During the 1848 Revolution, they acted as intermediaries between the insurgents and the government side. In 1870, two Polytechniciens became famous for their exploits in the war against the Prussians: Pierre Denfert-Rochereau, who led the resistance during the siege of Belfort, and Louis Faidherbe, who held on to the Nord-Pas-de-Calais region until the capitulation. During the First World War, 900 Polytechnique graduates and 200 students were killed. In recognition of their involvement in the military successes, the School's flag was granted the insignia of the Croix de la Légion d’Honneur and the Croix de Guerre. In another interesting detail, four Polytechnicien generals who contributed to the victory were made Marshals of France, the highest French military distinction: Joseph Joffre, Ferdinand Foch, Émile Fayolle and Michel Maunoury. During the Second World War, many Polytechniciens joined the Free French Forces, the BCRA (Central Office of Information and Action), and the French Resistance. 33 Polytechniciens were made Companions of the Liberation, 37 students in the classes of 1941 to 1944 were awarded Resistance medals and 60 Polytechniciens died after being deported, most of them for acts of Resistance. And X's involvement in the defense of France continues into modern times. In 1999, Caroline Aigle became the first female French fighter pilot, Pierre Marion was the first Director of the new DGSE (Directorate-General for External Security) in 1982, André Giraud created the CGA (General Council for Armaments) in 1988 and many Polytechniciens go on to join the DGA (Directorate-General for Armaments).