In May 1918 the Allied Supreme Commander, Ferdinand Foch and the British Commander-in-Chief, Sir Douglas Haig, began making plans for a counter-offensive on the Western Front. It was decided to make a surprise attack just south of the Somme.
The German offensive at Aisne in late May forced Foch to postpone the plan. When the German advance was brought to a halt at the Marne, Foch returned to his plan of a counter-offensive. Foch put Haig in overall charge of the offensive and he selected General Sir Henry Rawlinson and the British Fourth Army to lead the attack. The main objective of the operation was to capture the Amiens Line between Mericourt and Hangest.
Men and every available tank was moved to Rawlinson's sector. This included 72 Whippet and 342 Mark V tanks. Rawlinson also had 2,070 artillery pieces and 800 aircraft. The German sector chosen was defended by 20,000 soldiers and were outnumbered 6 to 1 by the attacking troops.
The Amiens offensive on 8th August 1918 was an immediate success. The tanks followed by soldiers met little resistance and by mid morning allied forces had advanced 12km. The Amiens line was taken, and later, General Erich Ludendorff, the man in overall charge of German military operations, described the 8th August as "the black day of the German Army in the history of the war.
After two days the advance slowed down. Once again the British Army had trouble with their tanks and by 12th August only six were in full working order. The Germans had also sent 12 divisions to the sector to fill the gap in the line. On 15th Sir Douglas Haig brought an end to the attack and began preparing for a new offensive at Albert.