In which month of 1917 did this battle during the World War I, in which Henry Maitland Wilson participated, start?
Henry Maitland Wilson Field Marshal Henry Maitland Wilson, 1st Baron Wilson, (5 September 1881 – 31 December 1964), also known as Jumbo Wilson, was a senior British Army officer of the 20th century. He saw active service in the Second Boer War and then during the First World War on the Somme and at Passchendaele. During the Second World War he served as General Officer Commanding-in-Chief (GOC-in-C) British Troops in Egypt, in which role he launched Operation Compass, attacking Italian forces with considerable success, in December 1940. He went on to be Military Governor of Cyrenaica in February 1941, commanding a Commonwealth expeditionary force to Greece in April 1941 and General Officer Commanding (GOC) British Forces in Palestine and Trans-Jordan in May 1941.
Douglas Haig, 1st Earl Haig Field Marshal Douglas Haig, 1st Earl Haig, {'1': ", '2': ", '3': ", '4': "} ( ; 19 June 1861 – 29 January 1928) was a senior officer of the British Army. During the First World War he commanded the British Expeditionary Force (BEF) on the Western Front from late 1915 until the end of the war. He was commander during the Battle of the Somme, the battle with one of the highest casualties in British military history, the Third Battle of Ypres, the German Spring Offensive, and the Hundred Days Offensive, which led to the armistice of 11 November 1918.