The defeat of the German cavalry in this action was decisive. It was not that they did not fight with bravery. They did. Broken in one charge they were rallied by their officers for another. Some four times in succession in the battle among the hills they attempted to recover.
While the British cavalry were carrying out their brilliant drive, the 3rd Army Corps advanced east from St. Omer to Hazebrouck. In the meantime also the 2nd Corps had taken up a line of positions along the canal from Bethune to Aire. Next day (October 12) the 2nd Corps moved forward to Merville, a little town south-east of the Forest of Nieppe.
The plan of the British operations may be briefly stated. Taking Givenchy, a village two miles west of La Bassee, as the pivoting point, it was intended to swing the line round until it reached the Lys. In this movement the British front would swing through a quarter circle, that is, from north-west to north-east. The British cavalry would be on the outer, or left wing; the inner, or right wing, at Givenchy would be hinged on to the French positions. In this way the country between the Lys and the sea would be cleared of the enemy, and the Allies envelopment carried from Givenchy past Lille, so that that important place could no longer be used by the Germans as a base for overrunning the country to the coast.
There was a further aim. This was to seize, if possible, the railway junction at Menin, ten miles north of Lille. The move would both embarrass the German occupation of Lille, and hamper the enemy in any attempt to throw troops in force over the Lys.
On the other hand, the immediate purpose of the Germans is equally clear. Not strong enough, as they judged, to risk a pitched battle; their right wing exposed by the defeat of their cavalry; and the probability owing to this unexpected appearance of the British army now being that the Belgians from Antwerp and the British troops from Ghent would get through, they determined to obstruct the British movement by guerrilla tactics, and until their main forces came up to defend in detachments the numerous and almost contiguous villages of the country, taking advantage of its network of canals and railways, and of its tangle of roads and cross roads. It is difficult to imagine what is in military language called a "close" country more difficult to operate in than this, one of the most densely populated areas of the world. The German scheme was to treat the civilian inhabitants with ruthlessness, wasting and plundering as they retired.
Manifestly, the success of the British movement would depend upon its energy. The Germans were fighting to gain time. Not stopping, therefore, at Merville, the 2nd Corps fought forward directly towards Lille by way of Laventie, in the valley of the Lys. Laventie, about ten miles west of Lille, is the centre of a dense semi-urban industrial district. Concurrently the 3rd Corps advanced eastward from Hazebrouck towards Bailleul. Seven miles to the south-west of Ypres, that place lies on the southern slope of the crescent of hills already referred to. Some scattered advance posts of the enemy were met with in intermediate villages, and were driven in. The Germans had taken up a position along the ridge from Berthen, between the Mont des Cats and Mont Noir on the north through St. Jans Cappel and Bailleul, and on the main road to Armentières. About two miles in advance of this line they held in force the villages of Fletre and Meteren, which they had fortified and barricaded.
The British attack began at daybreak on October 13. It was a day of rain and fog, one of those fogs which, in autumn, cover these flats with an almost impenetrable mist. Such conditions rendered movement over the low-lying sodden country slow. On the other hand, as against the British troops moving to the attack the conditions put the German guns out of action, and, what was not less material, they concealed the movements of the Allied cavalry. For by this time the French horse, under the command of General Conneau had arrived, and the plan of battle was that the French cavalry should assault and turn the left of the German position at Nieppe, on the main road from Bailleul to Armentières, thus cutting off the enemy from Lille, while the British cavalry attacked Berthen. In the meantime, the main assault would be delivered by the infantry against Bailleul, the centre of the hostile position.
Throughout the 13th the fighting raged round Fletre and Meteren. Both places were taken. Meteren was stormed in an onset which at nightfall drove the Germans who were holding it in a ragged rout to Bailleul. General Pulteney decided at once to follow up this advantage. An advance on Bailleul was immediately begun. All this while the cavalry on both wings had been active. At daybreak on October 14 the British horse broke into Berthen, and despite a bitter resistance drove the Germans out, and began to roll up their flank on that side. The French cavalry had got astride of the Armentières road. Realising that their whole force was in danger of being rounded up, the Germans took the chance offered by darkness, intensified by heavy rain, to beat a precipitate retreat. When the British infantry reached Bailleul, they found the town evacuated.
These operations opened up the way to Lys, and the 3rd Corps advanced on October 15 to the line of that river extending from Armentières to near Laventie. They thus came into line with the 2nd Corps, which, driving the Germans off the main road from La Bassee to Estaires, an important road junction on the Lys two miles above Sailly, had pushed on to Fournes. At that place, four miles east of Neuve Chapelle, and not more than seven from the centre of Lille, they cut the German communications between Lille and La Bassee.
Thus, at the end of four days, the British were both at Armentières and at Fournes, within seven miles of Lille, and formed with Laventie as the base of it, a front of almost a right angle, the apex pointing westward. At the same time the cavalry had received orders to continue their drive from Berthen across the country and down the valley of the Lys towards Menin.[4] In those four days the Germans had been driven back some twenty miles. Decidedly the surprise provided for them by the British army had been anything but agreeable.