The Siege of Soissons (11 September 1870 – 16 October 1870) was a military engagement during the Franco-Prussian War, ending with the capitulation of Soissons.
Background In 1870, the population of Soissons was 10,000, including both civilians and military. Following the Battle of Sedan, the Prussians advanced on Paris with parts of the Army of the Meuse. They then moved through the region and proceeded to surround Soissons on September 11, 1870. The French garrison stationed inside the fortress rejected initial Prussian demands to surrender, paving the way for a month-long siege.
Due to the topography of the area and the strength of the fortress, Prussian forces decided to besiege Soissons. Because the main Prussian advance on Paris had to be sped up, the frontline infantry - including the Prussian IV Corps - marched past the city. In their place, smaller cavalry detachments and reserve formations were left behind to isolate the fortress and keep Soissons under observation.https://archive.org/details/francogermanwar00stafgoog
On September 6, in anticipation of the Prussian advance, French forces executed scorched earth tactics around Soissons. The bridges between Villeneuve-Saint-Germain, Saint-Mard, Aisne, Missy-sur-Aisne, and Condere were destroyed. The French also detonated and collapsed sections of both the Vauxaillon and Vierzy railway tunnels.
On September 9, the presence of the White Cuirassiers 4th Corps, commanded by General Alvensleben, was reported in the district of Soissons. Following this, the Prussians sent their troops to the Wailly bridge, as it had not yet been destroyed.
Fortress modification Soissons' location was considered strategically important due to its position at the junction of three major roads and two railways, connecting Paris to both Reims and Laon by the Villers-Cotterêts. In addition, Soissons' bridge over the Aisne provided a convenient path to Paris. As the mountains surrounding Soissons were devoid of fortified works, the town was deemed tactically disadvantageous. On the eve of the war, Soissons was considered the "key to Paris" and represented one of the second-line strongholds on France's northeastern border. However, no preparations had been measured to bring the stronghold to a state of readiness consistent with its attributed strategic importance.
The fortifications within Soissons consisted of a continuous wall covered with 11 bastions. The enclosure was casemated in various places, but had not been designed to shelter the garrison. It was based on the Aisne to the north and to the south and formed a quadrilateral of approximately 1,200 meters by 800 meters. The Saint-Vaast suburb was not included in this quadrilateral but formed an enclosure leaning on the Aisne to the east and was covered with three bastions.
Two nearby valleys were partially flooded, alongside most of the ditches in the area. The floodwater was redirected from a military dam and nearby depression. Only a portion of the ditches in the southwest, due to their higher position, could not be flooded. These actions delayed Prussian advances for a time, but ultimately, Soissons was unable to withstand a prolonged siege.
Garrison
At the time of the declaration of war, the garrison of Soissons consisted of three battalions of the 15th Line Infantry Regiment, under the orders of Colonel Théodore Eugène Fraboulet de Kerléadec. The garrison was, however, without artillery teams. On July 20, the 15th RIL left Soissons to join the Army of the Rhine. On July 22, the arrival of brigades spoiler Sonnay and Colin of 3 E Division 6th Army Corps of the Army of the Rhine under the orders of General Lafond de Villiers, who joined on August 2nd the Châlons camp. From August 2 to the 10, the area was entirely unguarded. On August 11, under the Decree of July 17, 1870, which called the mobile guards under the flags, the 2nd mobile battalion of the Aisne (district of Soissons) garrisoned there. On August 12th, the 1st Battalion of mobile Aisne (district of Château-Thierry) arrived. On August 17, the 6th mobile battalion of Aisne (district of Vervins) arrived. At around the same date, the depot battalion of the 15th line infantry regiment arrived from Laon. The battalion was made up of 2 companies of 800 men each, with barely 10 officers to command them. They were reinforced by elements escaped from Sedan, which formed 2 additional companies. On August 20, the 1st battery of the 8th artillery regiment arrived. On August 27, the 1st Battalion of the Aisne Mobile was sent to Villers-Cotterêts and Paris. That same day, the government recalled former soldiers aged 25 to 35, who were armed with old piston rifles, and created the rural national guards. These were transformed into marching regiments. Thus, the 2 battalions of Soissons formed the 17th marching regiment.
At the start of the siege, the city was defended by around 4,425 men:1 engineering section of Exéa's division (30 men), 1 battery piece of the 8th artillery regiment (115 men) the Northern Mobile Artillery (230 men), the 12th North Mobile Artillery Battery, the 3rd North Mobile Artillery Battery, the 16th North Mobile Artillery Battery Soissonnais volunteer battery (50 men), the Deposit Company of the 15th Line Infantry Regiment 2nd Battalion mobile Aisne (1,200 men), and the 6th battalion of mobile Aisne (1,200 men).With the total workforce of around 550 men:1 company of firefighters, 1 company of volunteer national guards, about 15 gendarmes and 122 artillery pieces, of which only 51 were usable. This improvised troop, under the command of Lieutenant-Colonel de Noue, was made up largely of volunteers who lacked armament, equipment, instruction and discipline. The officers were non-commissioned officers and corporals appointed hastily.
Siege Prelude Ignoring the city, the German army continued its march towards Paris, advancing along local roads of the region and putting other targets aside for a later occasion in order not to slow down its march. This approach hastened the journey, as from Sedan to Paris, the Germans did not meet any French soldiers; only two fortified towns, Laon and Soissons, lay in their path.
September The city of Laon, commanded by General Thémérin, had a garrison consisting of only a battalion and a battery of artillery of the mobile guard. However, on September 8th, a strong detonation coming from the direction of Laon had been heard in Soissons; it was the powder keg that had blown. According to a contemporary report, the fortress of Soissons had received no orders or help from the French government since the Battle of Sedan on 1 September 1870, leaving the garrison isolated and without direction from Paris. On September 10th, a parliamentary dragoon officer of the 12th army corps appeared at the Porte Saint-Martin to request the surrender of Soissons. Colonel de Noue, the commander at Soissons, refused.
The long German columns continued to march around Soissons, towards Paris, and the city was promptly surrounded. On September 14th, a group of German cavalrymen attempted a reconnaissance on the Porte de Reims. They were driven out by cannon and rifle fire. The same day, a second parliamentarian demanded the surrender of the fort. In response to a new refusal, the Germans fired 3 cannon shots on the city from the heights of Sainte-Geneviève. On September 18th, warned by an inhabitant, a platoon of national guards in Venizel were surprised. On the same day, a detachment of about twenty Prussians was dispatched; one was killed, and the rest were taken prisoner. On September 22nd, 42 national guards carried out a coup de main against some German riders accompanying about sixty horses confined in to Beugneux; 1 officer and 2 German soldiers were killed, 18 were taken prisoner, and 50 horses captured.
On September 24th, 40 National Guards and the 15th line fire on the Prussian cavalry in The Cottage in Venizel. Alerted, a Prussian battalion, joined by 3 battalions of the Landwehr, forced the National Guards to fall back after a hard fight on the hill of Villeneuve. 2 French officers were killed, 8 men were wounded and 16 went missing; the Prussians suffered 2 dead and 15 wounded. Following this engagement, the Grand Duke of Mecklenburg, Frederick Francis II of Mecklenburg-Schwerin, sent the following telegram from Reims to the Ministry of War in Berlin:
A parliamentarian summoned Colonel de Noue again to return him the city, and faced with a new refusal, the German troops made their arrangements to invade the place by installing grand guard positions,La grand-garde ou les grand-gardes étaient les avant-postes they placed battalions on the Sainte-Geneviève plateau, in Billy-sur-Aisne and Venizel, and built shelters and defense works.
From September 25th, the Prussian positions were bombarded by the French cannons. However, this did not prevent the Prussians from extending their supply lines and occupying the station, which had been abandoned by the French. On September 26th, 200 men of the 15th line, accompanied by 100 men of the 2nd Battalion mobile Aisne, went out to chase the Prussians in the suburb of Reims and burn their shelters. Unable to flush out the Germans, the attackers returned to the square after having lost 2 men and 2 being wounded, while the enemy had lost 8 men. On September 27th, fire was set in the foundry and part of the houses in the Faubourg Saint-Crépin, in order to dislodge and drive away the Germans that were too close to the city walls, while many soldiers who had escaped from Sedan were arriving. On September 28th, the garrison tried to occupy the suburb of Reims and the station, which was stopped by the Prussians after 2 hours of fighting.
October On October 1st, Lieutenant-General von Selchow arrived in front of Soissons to lead the siege, with reinforcements made up of 7 infantry battalions, 4 cavalry squadrons, 2 field artillery batteries, and 2 pioneer companies. He established his headquarters at Carrière-l'Évêque, located behind Belleu and on the hill. He extended and reinforced the line of investment on the left bank of the Aisne and brought it as close as possible to the French outposts. The Maison-Rouge farm was occupied, as well as the cemetery blocking the road to Compiègne, through which the French troops had been able to leave until then. The right bank was occupied by 2 companies of landwehr and a squadron of white cuirassiers. The infantry positioned themselves at Crouy, Clémencin and behind the Laon railway embankment, with the cavalry at La Perrière in order to monitor the roads to Chauny and Laon. On October 3rd, a food convoy made up of 18 cars managed to enter the square after the French troops stationed in Soissons had opened the passage to Crouy:
On October 5th, by order of Colonel de Noue, the Vailly bridge was destroyed. "By order of the superior commander, the Vailly bridge must be destroyed. The guardian of the bridge, under penalty of treason, will have to let the order be carried out, if he warns the enemy, he will be brought before a council of war and shot. Soissons October 4, 1870. Signed De Noue."
On October 6th, informed of the destruction of the bridge, a detachment of around forty German cavalrymen entered Vailly and proceeded to arrest the mayor M. Mennessier and the councilor general of the canton M. Legry who were accused of "Criminal acts punished by the 4th paragraph of the Royal Order of 21 July 1867 and the rescript of paragraph 18 of the military Penal Code." The Prussians were taken to General de Selchow's headquarters at Carrière-l'Evêque, where he rendered the following judgment:
From October 7th to October 11th, the clashes continued: the besieged carried out harassment and bombing of outposts, while the besiegers, numbering 6,000 infantry, tightened their grip around the square.