During desperate and mutually costly German attacks, the III Corps, with some British and French reinforcements, was pushed back several times, in the 6th Division area on the right flank but managed to retain Armentières.

The new Lille garrison consisting of Territorial and Algerian mounted troops, took post to the south at Faches and Wattignies, linking with the rest of the 13th Division at Ronchin.

A German attack reached the railway and on 5 October, a French counter-attack recaptured Fives, Hellemmes, Flers-lez-Lille, the fort of Mons-en-Barœul and Ronchin; to the west, cavalry engagements took place along the Ypres Canal.

On 6 October, the 13th Division left two Chasseur battalions at Lille as XXI Corps moved south towards Artois and French cavalry near Deûlémont repulsed a German attack.

[8] Civilians from Lille, Tourcoing, Roubaix and neighbouring villages, left on foot for Dunkirk and Gravelines; several died of exhaustion and others were taken prisoner by German Uhlans.

The last train left Lille at dawn on 10 October, an hour after German artillery had begun to fire on the neighbourhood of the station, Prefecture and the Palais des Beaux Arts.

East of the line the land declines in a series of spurs into the Flanders plain, bounded by canals linking Douai, Béthune, Saint-Omer and Calais.

[10] From Kemmel, a low ridge lies to the north-east, declining in elevation past Ypres through Wytschaete, Gheluvelt and Passchendaele, curving north then north-west to Diksmuide where it merged with the plain.

The Lys, Yser and upper Scheldt had been canalised and between them the water level underground was close to the surface, rose further in the autumn and filled any dip, the sides of which then collapsed.

South of La Bassée Canal around Lens and Béthune was a coal-mining district full of slag heaps, pit heads (fosses) and miners' houses (corons).

North of the canal, the city of Lille, Tourcoing and Roubaix formed a manufacturing complex, with outlying industries at Armentières, Comines, Halluin and Menin, along the Lys river, with isolated sugar beet and alcohol refineries and a steel works near Aire-sur-la-Lys.

[13] Spurs ran south across the British line of advance and Mont des Cats and Flêtre were occupied by Höhere Kavallerie-Kommando 4 (HKK 4), with the 3rd, 6th and Bavarian Cavalry divisions, based at Bailleul.

On 12 October, the British cavalry advanced to make room for III Corps and captured the Mont des Cats at dusk, having made combined attacks by hussars, lancers and a horse artillery battery during the day.

A corps attack from La Couronne to Fontaine Houck began at 2:00 p.m. in wet and misty weather, which by evening had captured Outtersteene and Méteren, at a cost of 708 casualties.

On 14 October, rain and mist made air reconnaissance impossible but patrols found that the Germans had fallen back beyond Bailleul and crossed the Lys.

By evening Bailleul and Le Verrier were occupied and next day, an advance to the Lys began, against German troops and cavalry fighting delaying actions.

The III Corps closed up to the river at Sailly, Bac St Maur, Erquinghem and Pont de Nieppe, linking with the cavalry at Romarin.

The 6th Army attacked with the XIV, VII, XIII and XIX corps, intending to break through the Allied defences from Arras to La Bassée and Armentières.

The German infantry did not exploit the success and British troops on the northern flank were able to withdraw to a line 1 mi (1.6 km) west of Prémesques, between La Vallée and Chateau d'Hancardry.

After dark the 6th Division was ordered back to a shorter line from Touquet to Bois Blancs, Le Quesne, La Houssoie, Chateau d'Hancardry to ground about 400 yd (370 m) west of Epinette, the retirement on the right and centre being about 2 mi (3.2 km).

[23] On the 4th Division (Major-General Henry Maitland Wilson) front to the north, a German bombardment by heavy artillery began on Armentières at 8:00 a.m. which led to the III Corps headquarters being moved back to Bailleul.

[25] When established in Le Gheer, the German infantry fired on the British defences to the south, nearly caused a panic and outflanked the Cavalry Corps to the north from St Yves to Messines.

A counter-attack was made just after 9:00 a.m. by one battalion and two squadrons of lancers, which drove back the Germans and inflicted many losses, regaining the captured trench, except near the village of Le Touquet.

In the afternoon the village was attacked until nightfall, when a gap was forced in the Anglo-French defences and the defenders of Le Maisnil withdrew about 1,200 yd (1,100 m) to a reserve position at Bas Mesnil, leaving behind 300 men who were taken prisoner, including their wounded.

German troops of Infantry Regiments 122 and 125 of the 26th Division appeared to be unaware of the retirement, having strayed southwards after the capture of La Vallée earlier in the day.

Many German attacks were made from 22–23 October, particularly against the 16th Brigade, which held a south-facing salient with Le Quesne at the apex, 3 mi (4.8 km) south-east of Armentières.

A bigger German attack was made at dawn on 28 October, on an 18th Brigade battalion holding a salient east of the La Bassée–Armentières railway near Rue du Bois by infiltrating through ruined buildings.

By coincidence, big 6th Army attacks on the 4th Division front south of the river ended at the same time, which meant that the massing of reserves on the north bank could be done safely.

Artillery was concealed by ground features only but the small number of observation aircraft on both sides and the extent of tree cover, enabled guns to remain hidden.

German discipline and bravery was eventually defeated by the dogged resistance of the Allied soldiers, the effectiveness of French 75 mm field guns, British skill at arms, skilful use of ground and the use of cavalry as a mobile reserve.