British artillery fired a preparatory bombardment from Polygon Wood to Langemarck for the main attack due on 14 August but the German guns concentrated on the Gheluvelt Plateau.

British counter-battery fire was hampered by low cloud and rain, which made air observation extremely difficult and shells were wasted on empty gun emplacements.

[2] The 4th Army (General Friedrich Sixt von Armin) was responsible for defence of the Western Front from Lille to the North Sea, which included the Ypres Salient.

[3] The Germans were apprehensive of a British attempt to exploit the victory over Gruppe Wijtschate at Messines, with an advance to the Tower Hamlets (Bassevillebeek) spur beyond the north end of the ridge.

[10] From the Wilhelmstellung back to Flandern I Stellung was a rearward battle zone (rückwärtiges Kampffeld) containing support and reserve assembly areas for the Eingreif divisions.

It was anticipated that the main defensive engagement would take place in the Grosskampffeld with the reserve regiments and Eingreif divisions advancing against attackers who had been slowed and depleted by the forward garrisons.

Eingreif divisions were accommodated 10,000–12,000 yd (5.7–6.8 mi; 9.1–11.0 km) behind the front line and began their advance to assembly areas in the rückwärtiges Kampffeld, ready to intervene in the Grosskampffeld with an instant-immediate counter-thrust (den sofortigen Gegenstoß).

The Albrechtstellung contained 80 per cent of the Stoßkompanien and Stoßbatallione in divisional reserve and the local Eingreif division (composed of Stoß formations), was based in the rear positions.

Davidson also suggested that attacks should wait for two to three days of clear weather, to exploit the observation points gained on 31 July and two captured maps which showed the positions of camouflaged machine-gun nests.

Rupprecht made a diary entry, ...the results of the day's fighting were all the more satisfactory because the counter-attack divisions of Gruppe Wijtschate behind Gheluvelt Plateau had scarcely been used.in an order on 5 August, Gruppe Wijtschate announced that ...the enemy cannot continue his intended breakthrough...until he has gained freedom for his right flank by pressing back the 52nd Reserve Division on Gheluvelt Plateau....The next blow may therefore be expected to be delivered with the utmost strength against the 52nd Reserve and 12th Divisions.The rain that began on 31 July continued for three days and turned the ground into a morass about 4,000 yd (2.3 mi; 3.7 km) wide behind the new British front line.

The banks of streams became bogs with few crossing-places, easily visible from German positions and frequently bombarded, especially on the Gheluvelt Plateau, which delayed the consolidation of the captured ground.

[18] On the night of 9/10 August, both sides increased the volume of artillery-fire; several soldiers from British patrols were taken prisoner by the Germans and gave away the II Corps attack.

[19] The power of the German artillery behind the Gheluvelt Plateau after 31 July was undiminished and a continuous bombardment was maintained on the front line and rear areas of II Corps.

[20] The infantry were to advance behind a creeping barrage at 4:35 a.m., straight through to the second objective (black line) of 31 July, to capture the Albrechtstellung, Inverness Copse and Glencorse Wood across the neck of the plateau.

[23] Just after 6:00 a.m., German field guns and machine-guns began to barrage the Queen's start line and from Stirling Castle north to Westhoek, cutting off the British infantry from supplies and reinforcements.

On the right, some fusiliers reached Fitzclarence Farm and small engagements took place around the Albrechtstellung pillboxes, which resembled islands surrounded by a sea of mud; both sides captured and re-captured the fortresses in costly attacks and counter-attacks.

Enfilade fire from the south caused many casualties and the counter-attack nearly got behind the fusilier support company, forcing the British out from the most advanced posts, to a line about 200 yd (180 m) east of Clapham Junction.

The 11th Fusiliers had suffered so many casualties that an officer collected batmen, runners and pioneers to help with the defence, Lewis guns were used to cover a gap on the right and a company from the Middlesex Regiment took over the line north of the Menin road.

The Bedford were isolated, because the right-hand battalion of the 25th Division to the north had been stopped short of its objective and to the south, the 11th Royal Fusiliers had lost many casualties and not gained touch.

The garrison in Westhoek and two blockhouses in the village were taken by surprise and a deep slough of mud, up to 30 yd (27 m) wide, under 1 ft (0.30 m) of water in the Hanebeek Valley, protected the British from counter-attacks.

When a SOS rocket went unseen in the smoke and dusk at 7:15 p.m., a German counter-attack on the left flank was defeated by infantry small-arms fire, rifles being found to be particularly effective.

[37][b] To the south, on the right flank of RIR 90, the 5th and 6th companies were exhausted and had suffered many casualties; in the morning mist, thickened by smoke shells, the British achieved tactical surprise.

[38] A better-organised counter-attack with troops of the 10th and 11th companies, with four machine-guns attached from RIR 27, took place later in the morning after the fog had burned off; in the sunshine the German infantry struggled through the mud, sometimes needing to be pulled out.

As the Germans tried to negotiate the swampy banks of the Hanebeek, they were hit by British machine-gun fire from the positions on higher ground to the left, captured from the 52nd Reserve Division.

At 5:30 p.m. after much longer preparatory fire and a short hurricane bombardment, the counter-attack began again, reinforced by troops from RIR 238 on the right flank of the 52nd Reserve Division; the attack was a costly failure.

[40] In 1920, Malcolm Kincaid-Smith, the divisional historian, called the attack by the 25th Division a great success, the advance being conducted on schedule, supported by "excellent" artillery-fire.

The signal arrangements using daylight lamps worked all day, except on the left flank; runners maintained contact with the rear despite the German artillery and small-arms fire.

[43] In 1956, Wolfgang Foerster, the author of this volume of German official history, described the miserable living conditions of the troops in early August, the rise in the number of sickness cases and the casualties caused by the British artillery.

[45] In 2007, Jack Sheldon wrote that on 10 August, the battlefield was still a bog and the British preliminary bombardment failed to destroy all of the pillboxes and blockhouses west and south-west of Polygon Wood.

[46] J. P. Harris wrote in 2008 that although fresh divisions had been used and a strictly limited objective had been selected, the ground was too wet and lack of observation made British counter-battery fire ineffective.