In late 1914, conscious of the prospect of a lengthy war of position, the Germans began implementing a defensive strategy based on the fortification of their lines. They immediately began setting up their positions on favourable ground which is why, almost throughout the length of the front, the Allies found themselves at a disadvantage, either at the foot of high ground or in wet areas prone to stagnation.

Contrary to the long-term attitude of the Germans, the Allies' behaviour was conditioned by the view that the situation was a temporary one, their intention being to breakthrough the enemy's lines as soon as possible and force a decision in the resulting open ground. The German response to this strategy was to continue without respite the strengthening of their defences.

The effectiveness of the German system was demonstrated in tragic fashion during the British offensive on the Somme when, in July 1916, German soldiers survived a massive week-long preliminary bombardment unscathed. As the British infantry began to cross the no man's land, the German soldiers left their well-protected deep bunkers and manned their gun emplacements: 20,000 men were killed in one day while another 40,000 were either wounded or reported lost.

Drawing the obvious conclusions from the failed Allied offensive during the last Battle of the Somme, the German General Staff took the decision to build a new line of defence which was to be the supreme achievement in German military construction on the Western Front. The Siegfriedstellung, familiar to the Allies as the Hindenburg Line, was established far behind the existing front line (between ten and fifty kilometres). Structurally, it was a series of fortified zones linked together by defensive works which stretched from the North Sea to the town of Verdun.

Initially perceived by the Allies to be a sign of weakness, the decision to build a new line of defence, which would require a limited German retreat, was in fact an intelligent move. By withdrawing to a shorter and more easily defendable front the German Army could make better use of its troops and avoid the huge losses it had experienced at Verdun and on the Somme, losses it would not have been able to sustain in the long term.

Ludendorff decided that the retreat to the new line of defence would be accompanied by the systematic destruction of the newly abandoned zones, to deprive the Allies of any shelter, and the planting of mines and booby-traps to render the terrain dangerous as possible.

The Hindenburg Line comprised five operational zones, or Stellungen, which were named after figures of German mythology (from north to south): Wotan, Siegfried, Alberich, Brunhild, and Kriemhild. The most powerful of these sections was Siegfried which stretched 160 kilometres from Lens to Reims. It was built in just five months thanks to a massive workforce of more than 500,000 labourers including German civilians and Russian prisoners of war. The defensive works comprised deep trenches (5 m deep, 4 m wide) and dugouts with bands of barbed wire entanglements at least twenty metres wide in front of the front line. The pillboxes and shelters were protected by reinforced concrete and sheets of steel. In addition, a line of more lightly defended outposts were built about three kilometres in front of the main line to slow down any Allied attack. The battle zone proper, which was about two kilometres deep, was covered by a massive bank of big guns and machine-guns perfectly positioned to eliminate any advancing infantry. As the war progressed a series of anti-tank ditches were also dug in front of the front lines.

The Germans retreat towards the new defensive line took place in March 1917 so as to disrupt Nivelle's planned offensive, of which the German General Staff knew the main details. The Germans called their retreat Operation Alberich.

In 1918 the Hindenburg Line was the starting point of the Kaiserschlacht, the "emperor's battle", which the Germans launched on 21 March.

In September 1918 the Allies set forth with a huge number of tanks to break through the Hindenburg Line and by 10 October it had been completely overwhelmed. The Allied advance to victory was underway.

Yves LE MANER,
Director of La Coupole
History and Remembrance Centre of Northern France

• "The Hindenburg Line: the Apotheosis of German Fortifications on the Western Front in the Great War" by Dr David Payne, on the Western Front Association website