In which month of 1917 did this battle during the World War I, in which Henry Maitland Wilson participated, start?
Henry Maitland Wilson:  He saw active service in the Second Boer War and then during the First World War on the Somme and at Passchendaele. Battle of Passchendaele:  The battle took place on the Western Front, from July to November 1917, for control of the ridges south and east of the Belgian city of Ypres in West Flanders, as part of a strategy decided by the Allies at conferences in November 1916 and May 1917.
July