Eingreif division " Eingreif " division was a type of German Army formation of World War I established in 1917 , which was responsible for engaging in immediate counter - attacks against enemy troops who broke through a defensive position being held by a " front - holding " division ( ) . Definition . generally translated as counter - attack , but this does not capture the entire sense of the term . In German military doctrine it includes a sense of intervening decisively and is better understood as meaning interlocking . The term was adopted during the Battle of Arras ( 1917 ) as a replacement of an earlier term ( " relief division " ) to end confusion over the purpose of divisions held in reserve . During the First World War , the German army differentiated clearly between an organised counter - attack ( ) and a hasty counter - attack ( ) . The difference was largely to do with timings . A implied a formal , deliberate attack with full preparatory artillery fire . A was a hasty or immediate counter - thrust made to prevent the enemy from consolidating captured positions . The principal task of an division was to conduct the more immediate engagements , if troops held in reserve by the were insufficient to restore the position . To counteract the effect of an enemy penetration , these divisions were placed in readiness behind the trench system . The formation would have launched necessary manoeuvres in addition to the defensive efforts by the formation in situ . Evolution . German defensive practices had been based on the publication " Drill Regulations for the Infantry , German Army , 1906 " ( ) . After the experience of the 1916 Battle of the Somme , General Erich Ludendorff had German defensive doctrine revised . On 1 December 1916 , The Supreme Army Command published new tactical instructions in " Principles of Command in the Defensive Battle in Position Warfare " ( ) and issued it to all divisions . On 30 January 1917 , Ludendorff also circulated " Experience of the German First Army in the Somme Battles " ( ) by Colonel Fritz von Lossberg which contradicted the idea that troops in forward positions should be allowed to withdraw . The result was that German commanders had two examples to consider when arranging their defences . During the course of the Third Battle of Ypres , Lossberg ' s combination of forward defence and counter - attack from behind the front line was replaced by an elastic defence on Ludendorff ' s orders in October 1917 . The new thinking emphasised the defensive battle as a fight in defensive zones for the front line rather than in the front line , to defeat the attack or to gain time for a counter - thrust by forces held in local reserve . In a rear battle zone specially trained divisions , would be held back , ready to intervene with countering manoeuvres in support of the front zone garrisons . New deeper defensive positions composed of three defensive zones ( " outpost " , " battle " and " rear " ) which had been built according to the new manual ( Principles of Field Construction ) and held by garrison or " trench " divisions ( ) in a defensive battle ( ) . As the German army in the west was forced to make greater efforts in defence against Allied attacks in 1915 – 1917 , counter - attacks became more sophisticated . became counter - thrusts by local trench garrisons , while larger efforts by local reserves became ( counter - thrust from behind the position ) . As these practices developed , the role of the division was to execute an instant and immediate counter - thrust ( ) by moving to the front in stages to participate in a series of counter - thrusts . Application . The leading regiment of an Eingreif division was to advance into the zone of the front division with its other two regiments moving forward in close support . The support and reserve assembly areas in the Flandern Stellung were termed " Fredericus Rex Raum " and " Triarier Raum " by analogy with the formation of a Roman legion ( hastati , principes and triarii ) . Eingreif Divisions were accommodated behind the front line and began their advance to their assembly areas in the rear zone ( ) , ready to intervene in the main battle zone ( ) .