Action of 25 September 1917

Battle of Polygon Wood
Action of 25 September 1917
	Part of The Third Battle of Ypres, First World War
	; Map of the Ypres–Menin Road–Polygon Wood area, 1917
Date	25 September 1917
Location	West Flanders, Belgium50°51′7″N 2°59′7″E / 50.85194°N 2.98528°E
Result	German victory
Belligerents
German Empire	United Kingdom
Commanders and leaders
Crown Prince Rupprecht	Douglas Haig
Strength
2 regiments, 1 storm battalion	3 brigades
	Black Watch Corner class=notpageimage\| Site of the German Gegenangriff against the southern flank of the British advance of 20 September.

The action of 25 September 1917 was a German methodical counter-attack (Gegenangriff) which took place during the Third Battle of Ypres (31 July – 10 November) 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 1,800 yd (1,600 m) front. The Gegenangriff was supported by German aircraft and 44 field and 20 heavy batteries of artillery, four times the usual amount of artillery for a German division.

The German infantry managed to advance for about 100 yd (91 m) near the Menin road on the southern flank and 600 yd (550 m) 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 Wilhelmstellung 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, 1,000 yd (910 m) 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 2:00 p.m. 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.