The Battle of Loos was the largest British offensive on the Western Front in the World War I. This battle is known for the first poison gas use by the British and their New Army units. The Battle of Loos was an attempt to break the German defense in Champagne and Artois. French and British armies had more ammunition they were better equipped and had better methods, but still, their attacks were contained by the German forces. However, there were local ground losses. Casualties were high on French-British and German side.
The Battle of Loos is also known for the use of Royal Engineer tunnelling companies. They dug under the land between the armies and planted mines in front of the German trenches. Those mines should be detonated in zero hour.
There were 12 attacking battalions. They suffered 8.000 casualties in first 4 hours. They had 10.000 men. French lost his government support and he was criticized. He also lost army support, because of British poor handling and failure. French was replaced in December 1915 as the Commander of the British Expeditionary Force.
Britain lost 48.367 soldiers in the first attack. In other attacks, they lost 10.880 soldiers more. In total, the British lost 59.247 soldiers. On the Western Front, in 1915. They lost 285.107 soldiers. According to J. E. Edmonds, the British Official Historian, the Germans lost 26.000 soldiers (21 September – 10 October). During the offensive in Artois and Champagne they lost 141.000 soldiers. According to the Germans, the 6th Army lost 29.657 soldiers in September. By October, they lost 51.100 soldiers. This means that the Germans lost 150.000 soldiers at Artois and Champagne.