Natalis Constant Darche

Darche was appointed to command the fort at Longwy, near the border with Belgium and Luxembourg in 1912. The fort was one of the 18th-century Vauban fortifications and was long since obsolete.^[2] Anticipating a conflict with Germany, Darche installed new forward posts as close to the border as possible and established his first defensive line some 1,200 metres (1,300 yd) in advance of the fort. He also constructed outworks at Coulmy, Bel Arbre, Tilleul and Vieux Chateau. These were earthwork redoubts, open to the rear, and supplemented by a ditch and barbed wire. Located some 350–550 metres (380–600 yd) outside the fort walls they had no structures to shelter their garrison and were not expected to last long against a determined attack.^[3]

The First World War began in the Balkans on 28 July 1914. At this point Darche commanded around 3,500 men at Longwy including the 4th battalion and 5th territorial battalion of the 164th Infantry Regiment, a half-company of engineers, a company of customs officers and 5 battery and part of 25 battery of the 5th Foot Artillery Regiment.^[3] On 31 July Darche ordered three companies of the 164th Regiment to man his outworks and sent scouts out towards the border. The same evening he was ordered to remove part of his garrison to guard the Othain river in front of Marville, Meuse, and the Chiers river at Longuyon. Darche was placed under the command of the 2nd Army Corps under General Augustin Gérard, though communications with that unit were not established until 4 August.^[3]

Germany declared war on France on 3 August and from that point German cavalry began crossing the frontier and slipping past the fort; some probing attacks were made on the outer defences.^[4] By 8 August Longwy had been entirely circled by a screen of German cavalry.^[4] On 9 August significant forces of infantry and cavalry were sighted at Morfontaine and attacked by Darche's artillery.^[5] On the following day the German general Gustav von Hollen [de], commanding two cavalry divisions within Crown Prince Wilhelm's 5th Army, twice asked Darche to surrender and was twice refused.^[4]

After continued attacks, and surrounded with no hope of relief, Darche finally surrendered his command on 26 August. Darche's actions had held up the advance of the 5th Army for three weeks, preventing it from forming a link between the German advances in Lorraine and Belgium, to the German Emperor's displeasure.^[6][7] The loss of Longwy gave the Germans access to the Briey coalfield, their most valuable conquest in the first months of the war.^[2]

Darche had been appointed an officer of the Legion of Honour on the day before his surrender and was notified of this appointment by the Crown Prince.^[1][8] Darche was held as a prisoner of war in Germany. He was at Ingolstadt, Bavaria, in 1915 before being transferred to Marienburg, West Prussia. Darche fell ill and was evacuated to a hospital in neutral Switzerland on 18 June 1917. He was returned to France on 19 January 1918.^[1] Darche was appointed a commander of the Legion of Honour on 9 July 1920, by which time he was lieutenant colonel of the 35th Infantry Regiment.^[1] He retired to Meaux, Seine-et-Marne, where he died and was buried in 1947.^[9] A technical college, the Lycée Professionnel Darche, and a square, the Place du Colonel Darche, in Longwy are named in his honour.^[9][10]