The military planners considered a number of proposals. Foch agreed to a proposal by Field Marshal Sir Douglas Haig, commander-in-chief of the BEF, to strike on the River Somme, east of Amiens and south-west of the site of the 1916 Battle of the Somme, to force the Germans away from the vital Amiens–Paris railway. The Somme was chosen because it remained the boundary between the BEF and the French armies, along the Amiens–Roye road, allowing the two armies to cooperate. The Picardy terrain provided a good surface for tanks, unlike in Flanders, and the defences of the German 2nd Army under General Georg von der Marwitz were relatively weak, having been subjected to continual raiding by the Australians in a process termed peaceful penetration.