Question: In which month of 1917 did this battle during the World War I, in which Henry Maitland Wilson participated, start?
Sentence (from "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.
Relevant evidence: No