The Battle of Loos: A Costly First Attempt at Chemical Warfare in 1915
In September 1915, the British launched their largest offensive of the year at Loos, France. It marked the first time British forces used gas as a weapon, yet the operation struggled against German defenses, unpredictable winds, and the logistical challenges of deploying inexperienced New Army divisions in trench warfare.
The Battle of Loos, fought from 25 September to 8 October 1915, was a pivotal attempt by the British and French to break the stalemate on the Western Front. Following the failure of earlier 1915 offensives, General Joseph Joffre pushed for a breakthrough in Artois. Despite concerns from Field Marshal Sir John French and Douglas Haig regarding the terrain—overlooked by German-held slagheaps—the attack proceeded. The British deployed two corps, including the newly formed New Army divisions, aiming to push through German lines and restore a war of movement.
A defining feature of the battle was the first British use of chlorine gas. Following the German deployment of gas at Ypres in April 1915, the British abandoned their initial moral objections. At Loos, they used steel cylinders to release a greenish-yellow cloud, hoping the gas would sink into German dugouts. However, the plan was plagued by technical and environmental failures. In several sectors, light and shifting winds caused the gas to drift back into British lines, causing more casualties among their own troops than the enemy. Furthermore, the artillery bombardment proved insufficient to destroy German barbed wire and machine-gun nests.
The infantry assault saw early successes, with the 47th and 15th (Scottish) Divisions capturing the village of Loos and reaching Hill 70. Yet, the lack of immediate reserves and poor coordination meant these gains were fragile. By 1:00 p.m. on the first day, German reinforcements had recaptured Hill 70, effectively neutralizing the British breakthrough. The arrival of the 21st and 24th Divisions, which were inexperienced and had marched long distances, failed to turn the tide. Control on the front lines disintegrated during the night, and by the end of the battle, the British were forced to establish defensive lines well behind their initial objectives, underscoring the immense difficulty of overcoming entrenched German positions.
Source: Battle of Loos
