Source: Michael Doyle Their Name Liveth For Evermore: The Great War Roll of Honour for Leicestershire and Rutland.
He was the only son of the Reverend Canon William Vincent-Jackson, Rector of Bottesford, Leicestershire, and his wife Anne Gillespie who was the daughter of Thomas Mitchell. Montagu was educated at Bilton Grange School, and Marlborough College where he won a Foundation Scholarship, and two Open Scholarship’s. He obtained a Classical Scholarship and took Honours in Moderations at Oriel College, Oxford. He enlisted in the Special Public Schools Corps in August 1914, and later joined the Inss of Court O.T.C. He obtained a commission on the 13th November 1914, and served with the Expeditionary Force in France and Flanders from the end of August 1915. He was reported wounded and missing on the 5th February 1916, after being on night patrol near the enemy’s trenches. He was wounded twice, but owing to heavy fire his comrades were unable to bring him into the English lines. He was officially assumed to have been killed on or about that date. His Colonel wrote, “His loss is a very great blow to us all: he was commanding a Company and doing extremely good work. He was very poular with us all, and a harder worker I had not got.” A brother officer wrote, “I can assure you that your son was an extremely good officer, and a favourite such as it is given to few Battalion’s to have. He was loved and respected by all, officers and men alike, and I personally have lost a friend.” Montagu was unmarried. (See entry under VINCENT-JACKSON).