Noël Édouard Marie Joseph, Vicomte de Curières de Castelnau (24 December 1851 – 19 March 1944) was a French general in World War I. He represented the militant French Catholic element in the French Army, and headed the Fédération Nationale Catholique. Despite his significant achievements during the war, he was never named Marshal of France.
Born in Aveyron to an Occitan family with a long history in their home province of Languedoc. His father was a lawyer who had once been the mayor of St. Affrique. Édouard was described by a Literary Digest issue as a broadly-built man of short stature, with dark hair and a tan complexion, and a perpetually serious look. He joined the army in 1870 and fought in the Franco-Prussian War, 1870–71. He was Catholic and nicknamed le Capucin Botté (the fighting friar). In 1900 he was removed from the general staff for his anti-Dreyfusard attitude. Nevertheless he became deputy to Joseph Joffre 1911 to 1914. He helped to develop the strategic Plan XVII for the recapture of Alsace-Lorraine as part of an invasion of Germany. In 1914 he commanded Second Army the goal of advancing into German-held Lorraine. He was decisively defeated at the Battle of the Frontiers in August 1914. By the end of August, Castelnau won the Battle of the Trouée de Charmes and was able to organize a defence at Nancy and hold the city after victory in the Battle of Grand Couronné.
In June 1915 he was appointed to command the newly created Central Army Group. Later that year he was made chief of staff to Joffre, and in 1916 he organised the initial defence at the Battle of Verdun, before appointing Philippe Pétain to the command.
After the dismissal of Joffre and the appointment of Robert Nivelle in 1916 Castelnau was retired from active service. He was sent on the Allied Mission to Russia in the early months of 1917, just prior to the Fall of the Tsar. When Nivelle was dismissed and replaced with Philippe Pétain, Castelnau was recalled to the command of the Eastern Army Group where he commanded the advance into Lorraine in 1918.
Recognizing the hopelessness of modern trench warfare, he once remarked: "Ah, Napoleon, Napoleon. If he were here now, he'd have thought of something else." Three of Castelnau's sons were killed in the war.
After the war he entered politics. In 1919 he was elected to parliament as a deputy of Bloc National for Aveyron. In 1924 he founded the Fédération Nationale Catholique, which advanced a socio-religious model of France that has been described as "national Catholicism". In the same year Castelnau wrote an anti-Masonry pamphlet titled "La dictature de la maçonnerie en France" (The Dictatorship of the Masonry in France); he further publicized his accusations in a series of articles in Echo de Paris. Although his Catholic Federation reached one million members in 1925, its significance was short-lived and it subsided into obscurity by 1930.
Rue De Castelnau and De Castelnau metro station in Montreal are named after the general. School year n° 198 of the Ecole Speciale Militaire de Saint-Cyr (2011-2014) called Castelnau's school year" honours the general Castelnau.