The Allied forces and their commanders were taken by complete surprise when on 24th February 1917 it was clear that the Germans were making a strategic withdrawal away from their front-line positions to a much more heavily fortified position to the rear known as the Hindenburg Line. The fighting at Verdun and on the Somme of the previous year had a devastating impact on both sides, but the German High Command knew that their position was vulnerable once the expected Allied Spring offensive came so withdrawing to a stronger position and straightening the line meant that they could better man the defence of the French and Belgium territory they held with the same number of divisions. The new 100 mile line from Arras in the north to Soissons in the south, being constructed in quiet surroundings and chosen for their defensive qualities, would offer stronger and more comfortable shelter for the German troops in deep concrete shelters, protected by deep belts of wire entanglements. The Germans had at this stage recognised that their best chance of victory on land had probably gone, but by withstanding the coming onslaught would give their naval forces through their unrestricted use of their submarine fleet, time to create a blockade causing hardship, shortage of food and eventual inability of Britain to wage further war and seek peace terms from a German position of strength. The withdrawal would also disrupt the Allied planning, therefore buying more time for building the defence and for their submarines.
Once it was clear that German Army was in retreat, a period of cautious pursuit followed involving open country warfare and the use of new enveloping tactics as the advancing troops had to clear the stubborn German rear-guard whether in machine-gun positions and platoon sized pockets in sunken lanes, or manning the chain of outpost villages that lay before the Hindenburg Line. To the Australian troops advancing, the sight ahead of comparatively green valleys with buildings intact and trees still standing would have been a welcome lift after the months of the grey and mud filled cratered landscape of the Somme battlefield.
However as the Allies followed the German rear-guards, bitterness grew not just amongst the French but also in world opinion against the excesses of the German military in destroying everything in its wake for little military advantage. In front of the line a 15 kilometre belt was laid bare of houses and trees for shelter, and the roads, railways, bridges and water wells all destroyed and rendered useless. On the 17th March 1917, Bapaume, the objective for the great 1916 Somme offensive, was entered. For the infantry they had to be aware of booby-traps set in doorways, dugouts, and under boards, and in some cases such as the Bapaume Town Hall (photograph above where the 22nd Battalion were due to be billeted), time delayed mines. These tactics along with determined and skilful withdrawal of the German infantry using the countryside well, the progress to the Hindenburg Line was slow. I Anzac Corps arrived at the forward area overlooking the new German fortified front line on the Hindenburg Line at Bullecourt (photograph right) on 5th April 1917, just days before the great British Arras offensive was to due begin, giving the Australian artillery very little time to prepare for what would be the next major attack by the Australian Imperial Force during the First World War.