Map of the plan for the Allied Offensive in France showing the situation on September 24, the eve of the infantry assault. An Anglo-French would attack eastward in Artois (with the British at Loos) as the French attacked northwards in Champagne. From 'Military Operations France and Belgium, 1915, Vol. II, Battles of Aubers Ridge, Festubert, and Loos' by Brigadier-General J.E. Edmonds.
Situation, 24th September 1915Showing direction of the Allied offensive
September 25 to October 8, 1915
Western Front
In part to relieve the Russians, staggering before the German-Austro-Hungarian Gorlice-Tarnow Offensive of 1915, the Allies pressured German forces the length of the Western Front, bombarding them through August and September, from Switzerland to the Belgian coast, extending the shelling to ships along the coast, and conducting air raids on communications and supply lines. Even before the bombardment, British and French commanders met beginning in July to plan an offensive, agreeing on simultaneous Autumn attacks in Northern France. General Joseph Joffre's final plan called for a French offensive in Champagne along a front line running east-west, and British and French forces striking in Artois along a north-south line between La Bassée and Arras, with the British manning the line from La Bassée south to Lens, and the French continuing south to Arras. This would be the largest Allied offensive to date in numbers of men and artillery. Including cavalry, reserves, and reserve Belgian divisions, the Allies fielded 1,200,000 soldiers. After a four-day preliminary bombardment, the Allies advanced on September 25.
Under Field Marshal Sir John French, Generals Douglas Haig and Herbert Plumer commanded the British forces advancing towards Loos. The French 10th Army under Ferdinand Foch immediately to their south advanced towards Lens. General Édouard de Castelnau commanded the French 4th and 5th Armies in Champagne.
Hoping to achieve some element of surprise, the British used poison gas for the first time in the Battle of Loos. Some of the gas, released from cylinders and subject to the wind, blew back upon the British. Although the attack had some success and the city of Loos was taken, the British had inadequate reserves to break through the German line.
South of the British, the French had twice as many guns for each mile of the front as the British did, but the bombardment was still not enough to destroy the German barbed wire defenses. The attack, the Third Battle of Artois, failed in the attempt to seize Vimy Ridge.
In the Battle of Champagne, the French advanced with 35 divisions and some success, but the attack was stymied by the German second line of defense. General Pétain suspended the attack after three days.
Start Date: 1915-09-25
End Date: 1915-10-08