Two weeks later the British Expeditionary Force attacked at Cambrai. Tanks were used in large numbers for the first time and the Hindenburg Line was breached. However, this was a limited offensive - reserves were short, and despite the elated reception news of the battle enjoyed in Britain, it was not a fatal blow to German defences. The Germans counter-attacked in force and the British were forced to concede ground. By 3 December the battle was over. No breakthrough had occurred.
Russia's withdrawal from the war (due to the Russian revolution) allowed the Germans to transfer a large number of divisions to the Western Front, and in March they were ready to attack. The War Cabinet held back reinforcements for the Western Front and defences were not ready to meet an assault. The British, who had taken over an increasing share of the front line, were now stretched very thin.
The Germans first attacked on 21 March 1918 over a 50-mile section of the front between Lens and the Oise River. By 23 March the Germans were through British defences and into open countryside, pouring through a 40-mile wide hole. The British Fifth Army fell back in disorder. On 26 March the French appointed General Foch to command the allied armies in France. By the time the Germans called off the offensive, the British Fifth and Third armies had been thrown back as far as Amiens, and all the ground won in 1916 and 1917 was lost.
A week later the Germans attacked again along the River Lys. The British were forced to abandon all their gains for 1917 and retreated to the gates of Ypres. Having panicked the allies and captured much ground, the offensive came to a halt on 19 April 1918.
The final attack came in late May along the Chemin des Dames ridge north of the Aisne river, where a number of battered British divisions had been sent to rest. The Germans made gains of 13 miles, and by 3 June were only 39 miles from Paris. The British and French nearly lost their nerve (British politicians considered evacuating the British Expeditionary Force) but the allied forces finally managed hold their ground. The Germans began to lose very heavily, finding themselves relatively in the open compared to the heavy fortifications of the Hindenburg Line.
The Battle of Amiens was a spectacular victory. The allied attack began on 8 August 1918 and advanced eight miles by mid-afternoon, destroying six German divisions and provoking the mass surrender of about 50,000 Germans. The next day the BEF advanced another four miles. After the Battle of Amiens the Germans were forced to retreat from ground they had captured in the 1918 offensives. On 21 August the Third Army attacked and two days later the Fourth Army pushed the Germans back across the old 1916 Somme battlefield.
The BEF's First and Third Armies approached Cambrai on 27 September 1918, the Second Army approached Flanders a day later, and the Fourth Army approached the region of St Quinten the day after that. The Hindenburg line was breached, and on 5 October British troops moved into unfortified countryside. The Germans were forced further back in just over a month of fighting and the Armistice of 11 November 1918 marked the end of the First World War.