The Actions of the Bluff were local operations in 1916 carried out in Flanders during the First World War by the German 4th Army and the British Second Army. The Bluff is a mound near St Eloi, south-east of Ypres in Belgium, created from a spoil heap made during the digging of the Ypres–Comines Canal before the war. From 14 to 15 February and on 2 March 1916, the Germans and the British fought for control of the Bluff, the Germans capturing the mound and defeating counter-attacks only for the British to recapture it and a stretch of the German front line, after pausing to prepare a set-piece attack.
The fighting at the Bluff was one of nine sudden attacks for local gains made by the Germans or the British between the appointment of Sir Douglas Haig as commander in chief of the British Expeditionary Force (BEF), and the beginning of the Battle of the Somme. The BEF was at a tactical disadvantage, on low boggy ground, easily observed from German positions. A retirement to more defensible ground was impossible but rather than conserving manpower and resources with a tacit truce, the British kept an active front and five of the German local attacks in the period were retaliation for three British set-piece attacks.
The Germans had better weapons and with a homogenous army, could transfer troops and equipment along the Western Front easier than the Franco–British. The German army still had many pre-war trained officers NCOs and soldiers; the British wartime volunteers gained experience in minor tactics but success usually came from firepower; in the underground war, the BEF tunnellers overtook the Germans in technological ability and ambition. Capturing a portion of the opposing front line proved possible but holding it depended on the opponent. When the Bluff was captured, the British retook it; at the Battle of Mont Sorrel Mt Sorrel and Tor Top were retaken by the Canadians and British gains at St Eloi and Vimy Ridge were lost to German attacks. Had the British occupied the front less densely, more training could have taken place and the wisdom of each policy was debated at the time and since.
Background
Ypres district
Ypres is overlooked by Kemmel Hill to the south-west and from the east by low hills running south-west to north-east with Wytschaete (Wijtschate), Hill 60 to the east of Verbrandenmolen, Hooge, Polygon Wood and Passchendaele (Passendale). The high point of the ridge is at Wytschaete, from Ypres, while at Hollebeke the ridge is distant and recedes to at Polygon Wood. Wytschaete is about above the plain; on the Ypres–Menin road at Hooge, the elevation is about and at Passchendaele. The rises are slight apart from the vicinity of Zonnebeke, which has a gradient of From Hooge and to the east, the slope is near Hollebeke, it is heights are subtle but have the character of a saucer lip around Ypres. The main ridge has spurs sloping east and one is particularly noticeable at Wytschaete, which runs south-east to Messines (Mesen) with a gentle slope to the east and a to the west. Further south is the muddy valley of the Douve River, Ploegsteert Wood (Plugstreet to the British) and Hill 63. West of Messines Ridge is the parallel Wulverghem (Spanbroekmolen) Spur; the Oosttaverne Spur, also parallel, is to the east. The general aspect south of Ypres is of low ridges and dips, gradually flattening to the north into a featureless plain.
Possession of the higher ground to the south and east of Ypres gives ample scope for ground observation, enfilade fire and converging artillery bombardments. An occupier has the advantage of artillery deployments and the movement of reinforcements, supplies and stores being screened from view. The ridge had woods from Wytschaete to Zonnebeke, giving good cover, some being of notable size like Polygon Wood and those later named Battle Wood, Shrewsbury Forest and Sanctuary Wood. The woods usually had undergrowth but the fields in gaps between the woods were wide and devoid of cover. Roads in this area were usually unpaved, except for the main ones from Ypres, ribboned with occasional villages and houses. The lowland west of the ridge was a mixture of meadows and fields, with high hedgerows dotted with trees, cut by streams and ditches emptying into canals. The main road to Ypres from Poperinge to Vlamertinge is in a defile, easily observed from the ridge.