The Battle of Soissons (1918) (also known as the Battle of the Soissonnais and of the Ourcq ()) was fought on the Western Front during World War I. Waged from 18 to 22 July 1918 between the French (with American and British assistance) and the German armies, the battle was part of the Allied response to the German offensive launched on 15 July, which had launched the Second Battle of the Marne.
The primary objective of the Allied attack was to cut both the Soissons – Château-Thierry road and the railroad running south from Soissons to Château-Thierry. As these were the main supply routes for the German forces in the Marne salient, cutting them would severely impair the Germans' ability to supply its armies defending it, forcing them to retreat and give up their gains.
This battle marked the turning point of the war as the Germans would be on the defensive for the remainder of the conflict.
Background The Russian withdrawal from the war after the Treaty of Brest-Litovsk on 3 March 1918 freed 42 German divisions which had been fighting on the Eastern Front, providing a temporary numeric advantage over the Allies on the Western Front. The Germans realized their only remaining chance for victory on the Western Front was to defeat the Allies before the United States could fully mobilize, equip, and deploy their large manpower reserves. Beginning on 21 March 1918 the Germans launched a series of four offensives known as the 1918 Spring Offensive, or Kaiserschlacht (Kaiser’s Battle). By the end of the Spring Offensive, the German Army had inflicted heavy losses on the British and French armies and seized large amounts of territory, but had sustained heavy losses of their own and failed to create the conditions for final victory.
The resulting territorial gains resulted in the Germans occupying two vast salients on the Western Front. One salient was in the British sector between Arras on the Scarpe River and La Fère on the Oise River. The second was in the French sector from just west of Reims in the east to Noyon in the west and south to Château-Thierry.
Planning On 14 June, after the American 1st Division took Cantigny, Foch wrote to General Philippe Pétain, commander of the Armies of the North and Northeast, “I have the honor to invite your attention to the importance of the communications net at Soissons, which is used for the supply of four German divisions on the front and which constitutes at the same time the sole junction point of all the railroads available to the enemy on the Aisne and south thereof.”
Foch's letter to Pétain eventually reached General Charles Emmanuel Mangin, commander of the French Tenth Army. Mangin replied on 20 June with a summary plan for offensive operations to seize the plateau southwest of Soissons. From here long-range guns could subject the bridges and railroad network to a methodical and intensive bombardment. He stressed the importance of possession of the ridge of Villers-Hélon stating “it is on the heights of Villers-Hélon, and not in the low ground at Longpont Brook, that the defense of the forest of Villers-Cotterêts should be conducted. That same day Mangin submitted a plan of action for an exploratory attack to take some high ground west of Soissons.
On 23 June, at a conference in Chaumont, Pershing reminded Foch of the discussion they had at Sarcus where he suggested a counterattack. Foch replied, “studies are being made,” but made no mention of when, where, or whether such an attack would be made. Mangin's exploratory attack was executed on 28 June. According to Mangin, it “tended to prove” the Germans would have difficulty defending their positions against a surprise attack without artillery preparation. Additionally it would offer the best chance of success for an attack on the plateaus southwest of Soissons.
On 12 July, Pétain issued instruction No. 14546 to the generals of the Group of Armies of the Reserve and the Group of Armies of the Centre to make immediate preparations for an attack. He stated, "The minimum advantage gained should be to deprive the enemy of the use of the Soissons communication net." That same day Pétain issued instructions for an offensive whose purpose was to reduce the Marne salient. This would entail utilizing the French Tenth and Sixth Armies against the western flank of the salient, and the Fifth Army on the eastern flank. The French Tenth Army would carry out the main attack against the Soissons communication network. In support of the main attack, the French Sixth Army would attack south of the Ourcq River while the French Fifth Army would attack the eastern flank of the salient along both banks of the Ardre River with its right flank on the heights south of the Vesle River. At the very least the action of the French Fifth and Sixth Armies would result in preventing enemy reserves from moving against the main attack.
The following day Pétain stated the attack should be launched the morning of 18 July while stressing the necessity of secrecy. On 14 July both the American 1st Division and the American 2nd Division were transferred to the French Tenth Army XX Corps under General Pierre Emile Berdoulat.
On 15 July, the Germans opened what became the Second Battle of the Marne. General Max von Boehn, commander of the German Seventh Army, succeeded in getting seven divisions across the Marne. In response Pétain sent a message to General Émile Fayolle, commander of the Group of Armies of the Reserve, ordering him to “suspend the Mangin operation in order to enable me to send your reserves into the battle south of the Marne.” The message also ordered the return of the American 2nd Division artillery to the American 2nd Division. Within hours Foch brusquely rescinded the suspension of the Mangin operation, declaring “there can be no question at all of slowing up and less so of stopping the Mangin preparations."
Terrain Looking east from the Forêt de Retz, one would see an almost tree barren rolling plateau with waist-high wheat fields. Trench systems, the hallmark of First World War battlefields, were non-existent on this stretch of the front. The final objective, the road and rail network running south from Soissons in the Crise River valley, was about to the east and was hidden from view because of the sloping terrain.
Cutting across the plateau were a series of four deep, swampy, formidable ravines; Missy, Ploisy, Chazelle-Lechelle, and Vierzy. Villages, consisting of buildings constructed of sturdy stone masonry, were within and near the edges of these ravines. Substantial caves had been carved out to quarry the stone for the villages.
There were two main roads which stood between the final objective and the jump off point. The Soissons – Château-Thierry road ran due south, almost perpendicular, to the line of attack. The Soissons–Paris road ran southwest far from the American 1st Division jump-off point but crossing the American 2nd Division right at the jump-off point. These roadways were the principal lines of communication for the German troops in the Marne salient.
The railroad ran south from Soissons in the Crise River valley paralleling the Soissons – Château-Thierry road. At Noyant-et-Aconin it split with one branch turning southwest to Paris in the 2nd Division zone of attack. A second branch continued south through Oulchy-le-Château to Château-Thierry and also served as a principal line of communication.
The first major obstacle for the 1st Division was Missy Ravine, directly in the path of 2nd Brigade. This would allow 1st Brigade to make quicker progress until it had to contend with Chazelle Ravine further east. The 2nd Brigade would then have to deal with Ploisy Ravine beyond Missy Ravine. The 2nd Division would have to struggle with two arms of Vierzy Ravine, one of which cut completely across their sector. This meant that both the 1st and 2nd Divisions would have to contend with at least one ravine before the Moroccan 1st Division encountered the Chazelle-Léchelle Ravine.
Preparation Foch's desire was to achieve surprise of time and place. In order to achieve this, unusual precautions were taken limiting all information regarding the attack to the high command. On 14 July Fayolle issued a memorandum ordering the entire Group of Armies of the Reserve not to trust anyone not personally known to be reliable, move only at night, light no fires, and to report anything and anyone suspicious. In order to confuse the Germans as to his intentions Mangin chose to keep his artillery far back from the German forward areas in what the Germans considered a defensive posture: within range of the German front lines but unable to slow the arrival of enemy replacements or reinforcements. In order to keep the Germans off guard Mangin planned to have the two American divisions rush forward to the front just before the hour of attack.
The 1st and 2nd Divisions were in need of replacements after their engagements at Cantigny and Château-Thierry – Belleau Wood, respectively. Both divisions were brought to full strength with men from the 41st Division in early July. On 12 July, less than six days before the start of the attack, both the 1st and 2nd Divisions were assigned to the newly formed American III Corps which was attached to the French Sixth Army in the same order. Fayolle's Chief of Staff, General , sent a telegram two days later attaching both divisions to Mangin's Tenth Army.
At 11am on 16 July, Fayolle sent a telegram to the French General Headquarters stating that Mangin recommended there be no preparatory barrage prior to the attack of the French Tenth Army so as to achieve complete surprise. The telegram further recommended the attack begin at 4:35am behind a rolling barrage. The French Sixth Army, just to the south, would require a preparation barrage lasting one half hour. Fayolle left the start time of the barrage to General Jean Marie Degoutte, commander of the French Sixth Army, with the caveat the barrage not precede the French Tenth Army jump-off. At noon on 17 July 1918, Pétain approved Fayolle's recommendations and set 18 July 1918 as the attack date.
1st Division
The American 1st Division was bivouacked in the Forêt de Compiègne on 16 July and spent the entire day under cover of the woods to avoid detection by German aircraft. On 17 July, the division moved to the area near Mortefontaine, approximately from their jump-off point. At 9:00pm the division began to move eastward through the forest along trails cratered with shell holes. Soon after, a thunderstorm began turning the trails into a quagmire. Compelled to march off the trail and aided only by flashes of lightning, the infantry moved forward hanging onto the equipment of the man ahead to maintain the column.
2nd Division Paquette's order of transfer included orders for the 2nd Field Artillery Brigade of the American 2nd Division to move to Betz during the night of 14/15 July. Brigadier General Albert J. Bowley went ahead of the brigade to Chantilly to confer with General Mangin who confirmed the orders. He then had Bowley send the brigade to a point in the Forêt de Retz. At the same time the division trains and transports were ordered to concentrate under cover in the vicinity of Lizy-sur-Ourcq.