and forced the French to the south. The Territorial divisions retreated from Amiens on 30 August, skirmishing with German patrols near Cagny. On 11 September, the German garrison withdrew from Amiens and next day the Territorial divisions arrived from Rouen and captured a few stragglers. The Territorial divisions advanced to the north-east towards Péronne and Fricourt on 17 September. Prelude German offensive preparations General Erich von Falkenhayn replaced Colonel-General Helmuth von Moltke the Younger as Chief of the German General Staff on 14 September, when the German front in France was being consolidated in Lorraine and on the Aisne. The open western flank beyond the 1st Army and the danger of attacks from the National redoubt of Belgium, where the Siege of Antwerp had begun on 20 August, created a dilemma. The German positions in France had to be maintained, when only offensive operations could lead to decisive victory. Appeals for the reinforcement of the Eastern Front could not be ignored and Falkenhayn cancelled a plan for the 6th Army to break through near Verdun. The army was sent to the right wing of the German armies, where the flank of 1st army was at Compiègne, beyond which there were no German forces until Antwerp. Falkenhayn could reinforce the 1st Army with the 6th Army, send it to Antwerp or divide the army by reinforcing the 1st Army and the Antwerp siege with part of the army, while the rest operated in the area between. Falkenhayn chose to move the 6th Army to Maubeuge and outflank the Franco-British left wing, withdrawing the 1st, 7th and 2nd armies to La Fère, Laon and Reims while the 6th Army was redeploying. The 3rd, 4th and 5th armies were to defend if the French attacked first and then attack to the south-west beginning on 18 September. General Karl von Bülow, the 2nd Army commander and Colonel Gerhard Tappen of the Operations Branch of the (OHL, Supreme Army Command) objected because the time needed to move the 6th Army, would concede the initiative to the French. Bülow and Tappen recommended an attack by the 1st and 7th armies, with reinforcements from the armies to the east, for an offensive from Reims to Fismes and Soissons, since the French could redeploy troops on undamaged railways. The risk of separating the 1st and 2nd armies again would be avoided; Falkenhayn agreed and ordered the 6th Army