Victory in the Second Battle of the Marne at the beginning of August emboldened Marshal Foch, the Allied Supreme Commander, to order a full offensive on 8 August. It was decided to focus on Picardy rather than Flanders, as the terrain better suited tank warfare. The attack was broad based, aimed at the Amiens Salient, with the British leading the assault on the northern flank, the French hitting the south. The Germans were taken by surprise and overrun in what General Ludendorff termed the ‘Black day of the German army’; the Germans halted the advance, but only through drafting in their very last reserves. Scenting blood, Foch ordered the offensive to resume on 15 August, and on 21 August the French captured the Aisne Heights and joined battle for the town of Noyon. To the north, the British captured the town of Albert on 22 August.