Hindenburg Line

The Hindenburg Line (Siegfriedstellung or Siegfried Position) was a German defensive position of World

War I, built during the winter of 1916–1917 on the Western Front, from Arras to Laffaux, near Soissons on the Aisne. In 1916, the German offensive at the Battle of Verdun had been a costly failure. The Anglo-French offensive at the Battle of the Somme had forced a defensive battle on the Germans, leaving the western armies (Westheer) exhausted. On the Eastern Front, the Brusilov Offensive had inflicted huge losses on the Austro-Hungarian armies in Russia and forced the Germans to take over more of the front. The declaration of war by Romania had placed additional strain on the German army and war economy. Construction of the Hindenburg Line in France was begun by the Germans in September 1916, to make a retirement from the Somme front possible, to counter an anticipated increase in the power of Anglo-French attacks in 1917.

The shorter defensive position behind the Noyon Salient was built to economise on manpower, contain an Allied breakthrough and make possible a deliberate withdrawal to prepared positions. By destroying the infrastructure and demolishing civilian buildings in the salient before a withdrawal, the Germans could dislocate Franco-British offensive preparations, by forcing them to advance into a wasteland. The British and French armies would need about eight weeks to rebuild roads, bridges and railways in the abandoned area before they could attack. A shorter Western Front could be held with fewer troops and by incorporating the lessons of defensive battle on the Somme, the importance of troop dispersal, reverse-slope positions, defence in depth and camouflage, German infantry casualties could be reduced. While the German army recuperated from the losses of 1916, protected by the Hindenburg Line and similar defensive positions on the rest of the Western Front, a return to unrestricted submarine warfare and a strategic bombing offensive against Britain were planned.

By the beginning of 1917, the strategic outlook for the Germans made a retirement inevitable. German divisions on the Western Front numbered 133 on 25 January 1917, reducing the German manpower shortage but not by enough to contemplate an offensive. Greater output of explosives, ammunition and weapons by German industry to provide the means to counter the Allied Materialschlacht (battle of equipment) was attempted in the Hindenburg Programme of August 1916. Production did not sufficiently increase over the winter, with only 60 percent of the programme expected to be fulfilled by the summer of 1917. The German Friedensangebot (peace initiative) of December 1916, had been rejected by the Entente and the Auxiliary Service Law of December 1916, intended to further mobilise the civilian economy, had failed to supply the expected additional labour for war production.

The retirement to the Hindenburg Line took place as part of the Alberich Bewegung (Operation Alberich/Alberich Manoeuvre) from February–March 1917, after local withdrawals on the Somme had been forced on the 1st Army in January and February, by British attacks up the Ancre valley. News of the demolitions and the deplorable condition of French civilians left behind by the Germans, were serious blows to German prestige in neutral countries. Labour was transferred south in February 1917 to work on the Hundingstellung, from La Fère to Rethel and on the forward positions on the Aisne front, which the Germans knew were due to be attacked by the French armies. Divisions released by Operation Alberich and other reinforcements increased the number of divisions on the Aisne front to 38 by early April. The Hindenburg Line was attacked several times in 1917, notably at St Quentin, Bullecourt, the Aisne and Cambrai and was broken in September 1918, during the Hundred Days Offensive.

Battle of the Somme 1916
In August 1916 the German armies on the Somme had been subjected to great strain; the IX Reserve Corps had been "shattered" in the defence of Pozières. Ten fresh divisions had been brought into the Somme front and an extra division had been put into the line opposite the British. Movement behind the German front was made difficult by constant Anglo-French harassing-fire by artillery, which added to equipment shortages by delaying deliveries by rail and interrupting road maintenance. Destruction, capture, damage, wear and defective ammunition had caused 1,068 of 1,208 field guns and 371 of 820 heavy guns to be out of action by the end of August. The artillery situation was only slowly improved by the plan of General Max von Gallwitz, to centralise the command of the remaining artillery for counter-battery fire and to use reinforcements of aircraft to increase the amount of observed artillery fire, which had little effect on Allied air superiority but did eventually increase the accuracy and efficiency of German bombardments. The 2nd Army had been starved of reinforcements in mid-August, to replace exhausted divisions in the 1st Army and plans for a counter-stroke had been abandoned for lack of troops. The emergency in Russia caused by the Brusilov Offensive, the entry of Romania into the war and the French counter offensive at Verdun had already overstretched the German army.