The action of 25 September 1917 was a German methodical counter-attack (Gegenangriff) which took place during the Third Battle of Ypres on the Western Front during the First World War. On the front of the British X Corps (Lieutenant-General Thomas Morland) at the south-east side of the Gheluvelt Plateau, two regiments of the German 50th Reserve Division attacked on both sides of the Reutelbeek stream, on a front. The was supported by German aircraft and and batteries of artillery, four times the usual amount of artillery for a German division.
The German infantry managed to advance for about near the Menin road on the southern flank and on the northern flank beyond the Reutelbeek, close to Black Watch Corner. The attack was supported by artillery-observation aircraft, ground-attack aircraft and a box-barrage fired behind the British front-line, which isolated the British defenders from reinforcements and cut off the supply of ammunition. Return-fire from the 33rd Division south of Polygon Wood and the 15th Australian Brigade of the 5th Australian Division along the southern edge of the wood forced the attackers under cover. German parties re-captured several pillboxes of the near Black Watch Corner, which had fallen to the British during the Battle of the Menin Road Ridge (20 September) but attempts to reinforce the attackers failed.
General Herbert Plumer, the commander of the Second Army, ordered the attack scheduled for 26 September to go ahead but modified the objectives of the 33rd Division. The 98th Brigade was to advance and cover the right flank of the 5th Australian Division and the 100th Brigade to the south was to re-capture the lost ground. The depleted 98th Brigade was delayed and only managed to reach Black Watch Corner, short of its objectives. Reinforcements moved forward into the 5th Australian Division area to the north and attacked south-westwards at noon, combined with a frontal attack from Black Watch Corner. By the attack had succeeded despite massed machine-gun fire; later in the afternoon, the 100th Brigade re-took the lost ground north of the Menin road. Casualties in the 33rd Division were so great that it was relieved on 27 September by the 23rd Division.
Background
Strategic developments
The failure of the Kerensky Offensive in Russia in July had hastened the disintegration of the Russian army, the possibility of a Russian armistice and a huge reinforcement of the German Western Front. From 15 to 25 August, the Battle of Hill 70 was fought against the 6th Army by the Canadian Corps and forestalled the transfer of divisions to Flanders. On 20 August, the French attacked the German 5th Army at Verdun and in four days captured much of the remaining ground lost to the Germans in 1916 and took thirty guns, mortars and The Germans were not able to mount big counter-attacks, because their specialist counter-attack divisions (Eingreif divisions ) had been transferred to Flanders. French preparations continued for an offensive on the Chemin des Dames (the Battle of La Malmaison) in October and the British Third Army planned a surprise artillery and tank attack (the Battle of Cambrai) on the Flesquières Salient. France was running short of manpower; at the end of September, the French Minister of War had been told that another defeat could provoke more mutinies, which would be terminal for the French war effort. The British General Headquarters (GHQ) of the British Expeditionary Force (BEF) feared that the French might be forced into a separate peace.
Tactical developments
GHQ quickly studied the results of the attack of 31 July (the Battle of Pilckem Ridge) and on 7 August, sent questions to the Fifth Army headquarters about the new conditions produced by German defence-in-depth. The German 4th Army had spread strong points and pillboxes in the areas between its defensive lines and made rapid counter-attacks with local reserves and divisions against Allied penetrations. At the end of August, Haig moved the Fifth Army–Second Army boundary northwards and put the Second Army in charge of the main offensive effort on the Gheluvelt Plateau. Plumer issued a preliminary order on 1 September, which defined the Second Army area of operations as Broodseinde and the area to the south. The plan was based on the use of much more medium and heavy artillery.