The actions of the Hohenzollern Redoubt took place on the Western Front in World War I from 13 to 19 October 1915, at the Hohenzollern Redoubt () near Auchy-les-Mines in France. In the aftermath of the Battle of Loos (25 September – 8 October 1915), the 9th (Scottish) Division captured the strongpoint and then lost it to a German counter-attack. The British attack on 13 October failed and resulted in mostly in the first few minutes. In the History of the Great War, James Edmonds wrote that "The fighting [from 13 to 14 October] had not improved the general situation in any way and had brought nothing but useless slaughter of infantry".
Background
Strategic developments
In the summer of 1915 the German armies continued the strengthening of front trenches, communication trenches and strong-points ordered by Chief of the General Staff General Erich von Falkenhayn, who on 25 January had also ordered the building of more defensive lines behind the front trench. Crown Prince Rupprecht the Sixth Army commander and some Western Front generals had objected to this policy, as an invitation to German troops to retreat rather than fight. After the experience of the Battle of Festubert, where Allied artillery had proved capable of destroying a great width of front trench, opposition had been abandoned and the work carried on as quickly as possible. In early May Falkenhayn had also ordered that a second defensive position be built behind the whole of the Western Front, to force an attacker to pause to move artillery forward into range.
Plans to exploit the Franco-British superiority in numbers on the Western Front, while one third of the German army was on the Russian Front were agreed at a Conference by Joffre and French at Chantilly on 14 September. The British New Armies had begun to arrive, the number of heavy guns had increased since the offensives of May and June and by concentrating resources at the points of attack an even greater numerical superiority could be obtained over the Germans. An unprecedented preliminary bombardment of the German defences would be possible and make attacks by the greater number of Allied infantry decisive. Simultaneous offensives would be mounted from Champagne and Artois towards Namur, the principal attack being made in Champagne.
The attack by the French Tenth Army on Vimy Ridge in May and June had failed, which left the German Sixth Army in control of the high ground below which the French were to have assembled a mass of artillery and infantry. It was agreed that in Artois a Franco-British offensive would be mounted towards Douai, by the French Tenth and the British First armies, co-ordinated by General Foch on a front of between Arras and La Bassée canal. The British First Army was to attack between Grenay and La Bassée canal on a front, with six divisions and three in reserve. The Cavalry Corps and Indian Cavalry Corps were to be held ready to exploit a German collapse. The Franco-British armies were to attack towards Tournai, Valenciennes and Le Quesnoy and subsidiary attacks were to be made by the rest of the Franco-British armies to pin down German reserves.
Tactical developments
Field artillery available to the British divisions covered a front, with guns in support, while the Tenth Army divisional frontages were wide with guns. The smaller number of British guns was matched by a lack of ammunition. The offensives were to begin with a continuous and methodical bombardment for in which counter-battery fire was as important as trench destruction. A four-hour intense bombardment was to be fired, before the infantry attacks in Artois and Champagne began simultaneously on 25 September. The infantry were to advance as an "irresistible mass", with reserves arranged in depth to move forward at the same time as the leading troops, ready to take over and maintain the momentum of the assault. Previous attacks in Artois had been obstructed by the many villages and industrial premises in the region, which were easy for the Germans to fortify and use to delay attacks. The Franco-British heavy artillery was to be used to destroy German fortified houses and villages, which were proof against field artillery. Such tactics were expected to break through both German defensive positions and enable the cavalry to rush forward and widen the breakthroughs, before advancing on distant objectives in Belgium. If the attacks succeeded the rest of the Franco-British-Belgian armies would join in a general offensive and force the German armies into open warfare, in which Allied numerical superiority would be overwhelming.