At the outbreak of World War I, Nevinson joined the Friends' Ambulance Unit and was deeply disturbed by his work tending wounded French and British soldiers. For a very brief period he served as a volunteer ambulance driver before ill health forced his return to Britain. Subsequently, Nevinson volunteered for home service with the Royal Army Medical Corps. He used these experiences as the subject matter for a series of powerful paintings which used the machine aesthetic of Futurism and the influence of Cubism to great effect. His fellow artist Walter Sickert wrote at the time that Nevinson's painting "La Mitrailleuse", 'will probably remain the most authoritative and concentrated utterance on the war in the history of painting.' In 1917, Nevinson was appointed an official war artist, but he was no longer finding Modernist styles adequate for describing the horrors of modern war, and he increasingly painted in a more realistic manner. Nevinson's later World War One paintings, based on short visits to the Western Front, lacked the same powerful effect as those earlier works which had helped to make him one of the most famous young artists working in England.