The Battle of Mons was the first major action of the British Expeditionary Force during World War One. It was an auxiliary battle of the Battle of the Frontiers in which the British and French Entente forces clashed with the German forces. At Mons, the British attempted to hold the line against the advancing 1st German Army. Although the British inflicted substantial casualties on the Germans, they were forced to retreat due to German superiority and the retreat of the French 5th Army. The British retreat from Mons, also known as the Great Retreat, took the BEF to the outskirts of Paris.
Amidst all the mayhem of the Battle of the Frontiers, the BEF had been making its way to the front. The BEF was ridiculously small for a country with the imperial pretensions of Great Britain. Just four divisions and the equivalent of a cavalry division were sent to France under the command of General Sir John French.
The BEF was a highly trained force made up entirely of volunteer soldiers. Men served seven years with the colours and were then liable to a further five years in the reserves. The British Army had learned a great deal in the Boer War, but lacked any experience of modern warfare against a comparable European opponent. The defining characteristic of the BEF as a military force was its size: it was, as Kaiser Wilhelm II memorably put it, ‘a contemptible little army’, although this reflects German frustration more than any considered indictment.
The BEF had begun landing in France and then moved up to its designated concentration area at Maubeuge. The deployment had been somewhat delayed and it took 9 days for the BEF to edge into Belgium. The BEF reached the town of Mons. Despite reports of attacks on the neighboring French Army, coupled with cavalry and aerial reconnaissances, there was still a great deal of confusion as to the exact nature of the threat facing the BEF.
When Alexander von Kluck’s First Army crashed into Smith-Dorrien’s II Corps, the battle that ensued was to enter British military folklore. The myth is one of a heroic successful defence, with well-trained British ‘Tommies’ mowing down hordes of Germans repeatedly attacking in mass formations. In the end, the British would be forced to retreat only because the fickle French had given way on their right flank. The reality was very different. For one thing, the ‘battle-hardened’ British soldiers of legend were anything but. Some had gained experience more than a decade before in the Boer War, but they were in the minority.
It is undeniable that several of the British battalions fought well, but the Germans maneuvered skillfully to secure a local superiority against the weak points in the British defences. Wherever possible they operated against the flanks, forcing the British to fall back or risk being cut off and totally destroyed. The British were turned out of their defensive positions in a matter of a few hours and even failed to destroy several of the canal bridges. Both the immediate flanks were threatened and the Germans had broken through to seize Mons itself.
When the Great Retreat from Mons began, the BEF soon found that von Kluck’s First Army was in close pursuit. The I and II Corps were soon physically separated as they fell back on either side of the Forest of Mormal. The British tried to delay the German advance at Le Cateau. After the battle the French certainly thought the British had been beaten, and the Germans were convinced they had won. The German pursuit was complicated somewhat by von Kluck’s failure to correctly anticipate the direction of Smith-Dorrien’s retreat. Following Le Cateau, the whole of the BEF was in retreat.
Most officers and men had little idea where they were, where they were going or what was happening around them. There was a constant underlying fear. The ordinary soldiers were at the end of their tethers. After all, many were reservists who had been out of the Army for several years and were not in peak physical condition. In total, the Great Retreat lasted a little over a month.
Joffre perceived that the British needed a breathing space. He sent orders to Lanrezac to check his retreat and counterattack the German Second Army, treading close on its heels in its path towards Paris. Lanrezac’s instructions were to align Fifth Army along the upper course of the River Oise, to attack to the west where the river turned south to join the Seine at Pontoise. The battle – known to the French as Guise, to the Germans as St. Quentin – opened in the morning in thick mist. The Germans managed to resist the French counterattack and, after two days of fighting, reinitiate the pursuit. The French had to withdraw.
There were flashes of action, engagements between advance and rear guards, short, bitter little battles, such as that at Nery, where the British 1st Cavalry Brigade and L Battery, Royal Horse Artillery, held up the progress of the German 4th Cavalry Division for a morning. For the vast majority on both sides, however, the last week of August and the first of September were an ordeal of day-long marches, begun before the sun rose and concluded in the twilight.
Von Kluck's headquarters were installed in Louis XV's chateau at Compiègne. It was there that he received Moltke's wireless message directing his First Army to follow Bulow's Second ‘in echelon’ to the south-east, in order to cut the French off from Paris. Kluck decided to interpret the order literally, as giving him freedom to veer further eastward still in pursuit of Lanrezac's Fifth Army, to cross the River Marne and to initiate the decisive battle that Moltke actually intended to be delivered by the armies of the center, coming west from the Meuse. The German strategic effort, though neither Moltke nor Kluck perceived it, was beginning to fall apart.
The French created a new force, composed of a number of newly arrived and veteran divisions. The creation of this ‘mass of maneuver’ had been foreshadowed in Joffre's General Instruction No.2 of 25 August. Together they constituted the Armies of Paris, under the overall command of General Joseph Gallieni. Gallieni's demands provoked a government crisis. General Adolphe Messimy, finding himself blamed for the dangers of which Gallieni was now warning, insisted on being dismissed rather than accept a new appointment. By so doing, he brought about the resignation of the whole ministry. The political upheaval shook Joffre's imperturbability no more than the military setback.
Joffre disposed, at the opening of the great battle named after the river Marne, of thirty-six divisions, including the BEF, strengthened by the arrival of four fresh brigades from England, while the German First, Second, Third, Fourth and Fifth Armies opposing him consisted of just under thirty. The Germans were now outnumbered, as a result of Moltke's failure to control his subordinates and Joffre's refusal to be panicked by early defeat. It remained to be seen whether French generalship might yet pluck victory from the jaws of defeat.