The Second Battle of Champagne, 25 September-6 November 1915, was part of a wider Allied offensive launched in the autumn of 1915 (First World War). At the end of 1914 the active part of the German front line in France took the form of a giant salient, running south from the coast of Belgium to the Somme, and then turning east, running through the Champagne region to Verdun. South of Verdun the line was largely inactive. The Allied plans for 1915 called for attacks on the flanks of the German salient, in Artois and Champagne. The spring offensive had ended in failure (Second Battle of Artois), but that had not discouraged General Joffre, the French Command in Chief.
In June 1915 the Allies had met in the first inter-allied conference of the war. Britain, France, Belgium, Russian, Italy and Serbia had been represented, and all had agreed to coordinate their attacks. Circumstances intervened to prevent this from happening. The Battle of Gorlice-Tarnow (2 May-27 June 1915) broke the Russian front and forced a dramatic retreat out of occupied Poland. It was followed by a combined Austrian-German-Bulgarian invasion of Serbia in October 1915, the threat of which prevented any earlier Serbian offensives. Finally, the Italians launched the first of the eleven Battles of the Isonzo (23 June-7 July), without achieving anything. By the end of the year Second, Third and Fourth Isonzo would have repeated the failure.
This only left the British and French offensive on the Western Front. Initially it had been hoped to launch this attack in late August, but it took much longer than expected to build up sufficient supplies in Champagne to support a major offensive. Preparations included the construction of a new light railway line into the rear area. The attack was delayed, first to 8 September and then finally to 25 September.
This gave the Germans time to increase the strength of their defences. A new second line of defences was constructed, running three miles behind the first line. This alone would have made it almost impossible to achieve a breakthrough in a single day. Concrete machine gun posts were built between the two lines. The rear lines were normally built on the reverse slopes of any available high ground, making it much harder for the Allied artillery to bombard the German second line.
The attack was to be launched by German Pétain’s Second Army and General de Langle de Cary’s Fourth Army, under the overall command of General Castelnau. The attack was preceded by a length bombardment. Chlorine Gas was then released immediately before the infantry assault. On the morning of 25 September the attack went in (on the same day the attacks began in the Third Battle of Artois and at Loos).
As at Loos the initial assault went well. The German front line was overrun in several places, and French troops advanced towards the second line. That second line was almost entirely intact, and the French attack bogged down while the Germans rushed reinforcements to the area.
French assaults continued until the end of September. After a brief break they began again on 6 October, but without success. At the end of October the Germans launched a limited counterattack that recovered much of the ground they had lost on 25 September. By the time the battle was officially abandoned on 6 November, the French had lost 143,567 men. In some places they had advanced two and a half miles, but at no point had they captured the German second line of defences. German casualties were much lower, perhaps around 85,000 men, of whom 25,000 had been captured by the French. The battles in Artois and at Loos also ended in costly failure.